<PAGE>

                                                                   Exhibit 10.39
                                                                   -------------



                           BANYAN SYSTEMS INCORPORATED

                           Restricted Stock Agreement
                     Granted Under 1992 Stock Incentive Plan

  This Restricted Stock Agreement (this "Agreement") is made this 8th day of
October, 1999, between Banyan Systems Incorporated, a Massachusetts corporation
(the "Company"), and Scott G. Silk (the "Participant").

  For valuable consideration, receipt of which is acknowledged, the Company and
the Participant (each, a "Party" and together, the "Parties") each agree as
follows:

  1.     Purchase of Shares
         ------------------

  The Company shall issue and sell to the Participant, and the Participant shall
purchase from the Company, subject to the terms and conditions set forth in this
Agreement and in the Company's 1992 Stock Incentive Plan, as amended (the
"Plan"), 30,000 shares (the "Shares") of common stock, $0.01 par value per
share, of the Company ("Common Stock"), at a purchase price of $0.01 per share.
The aggregate purchase price for the Shares shall be paid by the Participant by
check payable to the order of the Company or such other method as may be
acceptable to the Company  upon receipt by the Company of payment for the
Shares, the Company shall issue to the Participant one or more certificates in
the name of the Participant for that number of Shares purchased by the
Participant.  The Participant agrees that the Shares shall be subject to the
Purchase Option set forth in Section 2 of this Agreement and the restrictions on
transfer set forth in Section 4 of this Agreement.

  2.     Purchase Option
         ---------------

      (a) In the event that the Participant ceases to be employed by the Company
for any reason or no reason, with or without cause, or the Participant announces
his intention to terminate his employment with the Company, prior to October 8,
2001, the Company shall have the right and option (the "Purchase Option") to
purchase from the Participant, for a sum of $0.01 per share (the "Option
Price"), any or all of the Unvested Shares (as defined below).

     "Unvested Shares" means the total number of Shares multiplied by the
Applicable Percentage at the time the Purchase Option becomes exercisable by the
Company. The "Applicable Percentage" shall be (i) 100% during the 12-month
period ending October 8, 2000, (ii) 50% during the 12-month period ending
October 8, 2001 and (iii) zero on or after October 8, 2001.
<PAGE>

      (b) In the event that the Participant's employment with the Company is
terminated by reason of death or disability, the number of the Shares for which
the Purchase Option becomes exercisable shall be fifty percent (50%) of the
number of Unvested Shares for which the Purchase Option would otherwise become
exercisable.  For this purpose, "disability" shall mean the Participant's
absence from the full-time performance of the Participants's duties with the
Company for 180 consecutive calendar days as a result of incapacity due to
mental or physical illness which is determined to be total and permanent by a
physician selected by the Company or its insurers and reasonably acceptable to
the Participant or the Participant's legal representative.

      (c) For purposes of this Agreement, employment with the Company shall
include employment with Banyan Systems Incorporated only.

      (d)   If a Change in Control Date (as defined below) occurs on or prior to
October 8, 2001, the Applicable Percentage shall be zero.  The following
definitions apply to this provision:

          (i) "Change in Control" means an event or occurrence set forth in any
one or more of Section 2(d)(i)(A) through 2(d)(i)(D) below (including an event
or occurrence that constitutes a Change in Control under one of such Sections
but is specifically exempted from another such Section):

          (A) the acquisition by an individual, entity or group (within the
meaning of Section 13(d)(3) or 14(d)(2) of the Securities Exchange Act of 1934,
as amended (the "Exchange Act")) (a "Person") of beneficial ownership of any
capital stock of the Company if, after such acquisition, such Person
beneficially owns (within the meaning of Rule 13d-3 promulgated under the
Exchange Act) 50% or more of either (1) the then-outstanding shares of common
stock of the Company (the "Outstanding Company Common Stock") or (2) the
combined voting power of the then-outstanding securities of the Company entitled
to vote generally in the election of directors (the "Outstanding Company Voting
Securities"); provided, however, that for purposes of this Section 2(d)(i)(A),
the following acquisitions shall not constitute a Change in Control: (1) any
acquisition directly from the Company (excluding an acquisition pursuant to the
exercise, conversion or exchange of any security exercisable for, convertible
into or exchangeable for common stock or voting securities of the Company,
unless the Person exercising, converting or exchanging such security acquired
such security directly from the Company or an underwriter or agent of the
Company), (2) any acquisition by the Company, (3) any acquisition by any
employee benefit plan (or related trust) sponsored or maintained by the Company
or any corporation controlled by the Company, or (4) any acquisition by any
corporation pursuant to a transaction which complies with clauses (1) and (2) of
Section 2(d)(i)(C) hereof; or

          (B) such time as the Continuing Directors (as defined below) do not
constitute a majority of the Board (or, if applicable, the Board of Directors of
a successor corporation to the Company), where the term "Continuing Director"
means at any date a member of the Board (1) who was a member of the Board on the
date of the execution of this Agreement or (2) who was nominated or elected
subsequent to such date by at least a majority of the directors who were
Continuing Directors at the time of such nomination or election or whose

                                       2
<PAGE>

election to the Board was recommended or endorsed by at least a majority of the
directors who were Continuing Directors at the time of such nomination or
election; provided, however, that there shall be excluded from this clause (2)
any individual whose initial assumption of office occurred as a result of an
actual or threatened election contest with respect to the election or removal of
directors or other actual or threatened solicitation o proxies or consents, by
or on behalf of a person other than the Board; or

          (C) the consummation of a merger, consolidation, reorganization,
recapitalization or statutory share exchange involving the Company or a sale or
other disposition of all or substantially all of the assets of the Company (a
"Business Combination"), unless, immediately following such Business
Combination, each of the following two conditions is satisfied: (1) all or
substantially all of the individuals and entities who were the beneficial owners
of the Outstanding Company Common Stock and Outstanding Company Voting
Securities immediately prior to such Business Combination beneficially own,
directly or indirectly, more than 50% of the then-outstanding shares of common
stock and the combined voting power of the then-outstanding securities entitled
to vote generally in the election of directors, respectively, of the resulting
or acquiring corporation in such Business Combination (which shall include,
without limitation, a corporation which as a result of such transaction owns the
Company or substantially all of the Company's assets either directly or through
one or more subsidiaries) (such resulting or acquiring corporation is referred
to herein as the "Acquiring Corporation") in substantially the same proportions
as their ownership, immediately prior to such Business Combination, of the
Outstanding Company Common Stock and Outstanding Company Voting Securities,
respectively; and (2) no Person (excluding the Acquiring Corporation, or any
employee benefit plan (or related trust) maintained or sponsored by the Company
or by the Acquiring Corporation) beneficially owns, directly or indirectly, 50%
or more of the then-outstanding shares of common stock of the Acquiring
Corporation, or of the combined voting power of the then-outstanding securities
of such corporation entitled to vote generally in the election of directors
(except to the extent that such ownership existed prior to the Business
combination); or

               (D) approval by the stockholders of the Company of a complete
liquidation or dissolution of the Company.

          (ii) "Change in Control Date" means the date on which a Change in
Control occurs.  Anything in this Agreement to the contrary notwithstanding, if
(A) a Change in Control occurs, (B) the Participant's employment with the
Company is terminated prior to the date on which the Change in Control occurs,
and (C) it is reasonably demonstrated by the Participant that such termination
of employment (X) was at the request of a third party who has taken steps
reasonably calculated to effect a Change in Control or (Y) otherwise arose in
connection with or in anticipation of a Change in Control, then for all purposes
of this Agreement the "Change in Control Date" shall mean the date immediately
prior to the date of such termination of employment.

                                       3
<PAGE>

   3.  Exercise of Purchase Option and Closing
       ---------------------------------------

      (a) The Company may exercise the Purchase Option by delivering or mailing
to the Participant (or the Participant's estate), within 60 days after the
termination of the employment of the Participant with the Company, a written
notice of exercise of the Purchase Option. Such notice shall specify the number
of Shares to be purchased. If and to the extent the Purchase Option is not so
exercised by the giving of such a notice within such 60-day period, the Purchase
Option shall automatically expire and terminate effective upon the expiration of
such 60-day period.

      (b) Within 10 days after delivery to the Participant of the Company's
notice of the exercise of the Purchase Option pursuant to subsection (a) above,
the Participant (or the Participant's estate) shall, pursuant to the provisions
of the Joint Escrow Instructions referred to in Section 8, tender to the Company
at its principal offices the certificate or certificates representing the Shares
which the Company has elected to purchase in accordance with the terms of this
Agreement, duly endorsed in blank or with duly endorsed stock powers attached
thereto, all in form suitable for the transfer of such Shares to the Company.
Promptly following its receipt of such certificate or certificates, the Company
shall pay to the Participant the aggregate Option Price for such Shares
(provided that any delay in making such payment shall not invalidate the
Company's exercise of the Purchase Option with respect to such Shares).

      (c) After the time at which any Shares are required to be delivered to the
Company for transfer to the Company pursuant to subsection (b) above, the
Company shall not pay any dividend to the Participant on account of such Shares
or permit the Participant to exercise any of the privileges or rights of a
stockholder with respect to such Shares, but shall, in so far as permitted by
law, treat the Company as the owner of such Shares.

      (d) The Option Price may be payable, at the option of the Company, in
cancellation of all or a portion of any outstanding indebtedness of the
Participant to the Company or in cash (by check) or both.

      (e) The Company shall not purchase any fraction of a Share upon exercise
of the Purchase Option, and any fraction of a Share resulting from a computation
made  pursuant to Section 2 of this Agreement shall be rounded to the nearest
whole Share (with any one-half Share being rounded upward).

      (f) The Company may assign its Purchase Option to one or more persons or
entities.

   4.  Restrictions on Transfer
       ------------------------

   The Participant shall not sell, assign, transfer, pledge, hypothecate or
otherwise dispose of, by operation of law or otherwise (collectively "transfer")
any Shares, or any interest therein, that are subject to the Purchase Option,
except that the Participant may transfer such Shares to or for the benefit of
any spouse, child or grandchild, or to a trust for their benefit, provided that
                                                                  --------
such

                                       4
<PAGE>

Shares shall remain subject to this Agreement (including without limitation
the restrictions on transfer set forth in this Section 4 and the Purchase
Option), and such permitted transferee shall, as a condition to such transfer,
deliver to the Company a written instrument confirming that such transferee
shall be bound by all of the terms and conditions of this Agreement; or

   5.  Effect of Prohibited Transfer
       -----------------------------

   The Company shall not be required (a) to transfer on its books any of the
Shares which shall have been sold or transferred in violation of any of the
provisions set forth in this Agreement, or (b) to treat as owner of such Shares
or to pay dividends to any transferee to whom any such Shares shall have been so
sold or transferred.

   6.  Escrow
       ------

   The Participant shall, upon the execution of this Agreement, execute Joint
Escrow Instructions in the form attached to this Agreement as Appendix A.  The
Joint Escrow Instructions shall be delivered to the escrow agent thereunder.
The Participant shall deliver to such escrow agent a stock assignment duly
endorsed in blank and hereby instructs the Company to deliver to such escrow
agent, on behalf of the Participant, the certificate(s) evidencing the Shares
issued hereunder. Such materials shall be held by such escrow agent pursuant to
the terms of such Joint Escrow Instructions.

   7.  Restrictive Legend
       ------------------

   All certificates representing Shares shall have affixed thereto a legend in
substantially the following form, in addition to any other legends that may be
required under federal or state securities laws:

        "The shares of stock represented by this certificate are subject to
        restrictions on transfer and an option to purchase set forth in a
        certain Restricted Stock Agreement between the corporation and the
        registered owner of these shares (or his predecessor in interest), and
        such Agreement is available for inspection without charge at the office
        of the Secretary of the corporation."

   8.  Provisions of the Plan
       ----------------------

   This Agreement is subject to the provisions of the Plan, a copy of which is
furnished to the Participant with this Agreement.

   9.  Withholding Taxes; Section 83(b) Election
       -----------------------------------------

      (a) The Participant acknowledges and agrees that the Company has the right
to deduct from payments of any kind otherwise due to the Participant any
federal, state or local taxes of any kind required by law to be withheld with
respect to the purchase of the Shares by the Participant or the lapse of the
Purchase Option.

                                       5
<PAGE>

      (b) The Participant acknowledges that he has been informed of the
availability of making an election in accordance with Section 83(b) of the
Internal Revenue Code of 1986, as amended; that such election must be filed with
the Internal Revenue Service within 30 days of the transfer of shares to the
Participant; and that the Participant is solely responsible for making such
election.

   10.  Severability
        ------------

   The invalidity or unenforceability of any provision of this Agreement shall
not affect the validity or enforceability of any other provision of this
Agreement, and each other provision of this Agreement shall be severable and
enforceable to the extent permitted by law.

   11.  Waiver
        ------

   Any provision for the benefit of the Company contained in this Agreement may
be waived, either generally or in any particular instance, by the Board of
Directors of the Company.

   12.  Binding Effect
        --------------

   This Agreement shall be binding upon and inure to the benefit of the Company
and the Participant and their respective heirs, executors, administrators, legal
representatives, successors and assigns, subject to the restrictions on transfer
set forth in Section 4 of this Agreement.

   13.  Notice
        ------

   All notices, instructions and other communications given hereunder or in
connection herewith shall be in writing. Any such notice, instruction or
communication shall be sent either (i) by registered or certified mail, return
receipt requested, postage prepaid, or (ii) prepaid via a reputable nationwide
overnight courier service, in each case addressed to the Company at Vice
President, Human Resources, Banyan Systems Incorporated, 120 Flanders Road, P.O.
Box 5013, Westboro, Massachusetts 01581-5013, and to the Participant at 30
Partridge Lane, Boxford, MA 01921 (or to such other address as either the
Company or the Participant may have furnished to the other in writing in
accordance herewith). Any such notice, instruction or communication shall be
deemed to have been delivered five business days after it is sent by registered
or certified mail, return receipt requested, postage prepaid, or one business
day after it is sent via a reputable nationwide overnight courier service.
Either Party may give any notice, instruction or other communication hereunder
using any other means, but no such notice, instruction or other communication
shall be deemed to have been duly delivered unless and until it actually is
received by the Party for whom it is intended.

                                       6
<PAGE>

   14.    Pronouns
          --------

          Whenever the context may require, any pronouns used in this Agreement
          shall include the corresponding masculine, feminine or neuter forms,
          and the singular form of nouns and pronouns shall include the plural,
          and vice versa.

   15.    Entire Agreement
          ----------------

          This Agreement and the Plan constitute the entire agreement between
          the Parties, and supersede all prior agreements and understandings,
          relating to the subject matter of this Agreement.

   16.    Amendment
          ---------

   This Agreement may be amended or modified only by a written instrument
executed by both the Company and the Participant.

   17.    Governing Law
          -------------

   This Agreement shall be construed, interpreted and enforced in accordance
with the internal laws of the Commonwealth of Massachusetts without regard to
any applicable conflicts of laws.

   IN WITNESS WHEREOF, the Parties have executed this Agreement as of the day
and year first above written.

                            BANYAN SYSTEMS INCORPORATED

                            By:  /s/ William P. Ferry
                                 -----------------------------------
                                 Name: William P. Ferry
                                 Title:  Chairman and
                                         Chief Executive Officer

                            PARTICIPANT

                                 /s/ Scott G. Silk
                                --------------------------------
                                Name:    Scott G. Silk

                                       7
<PAGE>

                                                                      Appendix A
                                                                      ----------

                          BANYAN SYSTEMS INCORPORATED

                           Joint Escrow Instructions




                                October 8, 1999

Richard M. Spaulding
Clerk
Banyan Systems Incorporated
120 Flanders Road
P.O. Box 5013
Westboro, Massachusetts 01581-5013

Dear Sir:

   As Escrow Agent for Banyan Systems Incorporated, a Massachusetts corporation
(the "Company"), and the undersigned person ("Holder"), you are hereby
authorized and directed to hold the documents delivered to you pursuant to the
terms of that certain Restricted Stock Agreement (the "Agreement") of even date
herewith, to which a copy of these Joint Escrow Instructions is attached, in
accordance with the following instructions:

   1.   Appointment
        -----------

        Holder irrevocably authorizes the Company to deposit with you any
certificates evidencing Shares (as defined in the Agreement) to be held by you
hereunder and any additions and substitutions to said Shares.  Holder does
hereby irrevocably constitute and appoint you as his attorney-in-fact and agent
for the term of this escrow to execute with respect to such Shares all documents
necessary or appropriate to make such Shares negotiable and to complete any
transaction herein contemplated. Subject to the provisions of this paragraph 1
and the terms of the Agreement, Holder shall exercise all rights and privileges
of a stockholder of the Company while the Shares are held by you.

   2.   Closing of Purchase
        -------------------

     (a)  Upon any purchase by the Company of the Shares pursuant to the
Agreement, the Company shall give to Holder and you a written notice specifying
the
<PAGE>

purchase price for the Shares, as determined pursuant to the Agreement, and the
time for a closing hereunder (the "Closing") at the principal office of the
Company. Holder and the Company hereby irrevocably authorize and direct you to
close the transaction contemplated by such notice in accordance with the terms
of said notice.

     (b)  At the Closing, you are directed (a) to date the stock assignment form
or forms necessary for the transfer of the Shares, (b) to fill in on such form
or forms the number of Shares being transferred, and (c) to deliver same,
together with the certificate or certificates evidencing the Shares to be
transferred, to the Company against the simultaneous delivery to you of the
purchase price for the Shares being purchased pursuant to the Agreement.

   3.   Withdrawal
        ----------

     The Holder shall have the right to withdraw from this escrow any Shares as
to which the Purchase Option (as defined in the Agreement) has terminated or
expired.

   4.   Duties of Escrow Agent
        ----------------------

     (a) Your duties hereunder may be altered, amended, modified or revoked only
by a writing signed by all of the parties hereto.

     (b) You shall be obligated only for the performance of such duties as are
specifically set forth herein and may rely and shall be protected in relying or
refraining from acting on any instrument reasonably believed by you to be
genuine and to have been signed or presented by the proper party or parties.
You shall not be personally liable for any act you may do or omit to do
hereunder as Escrow Agent or as attorney-in-fact of Holder while acting in good
faith and in the exercise of your own good judgment, and any act done or omitted
by you pursuant to the advice of your own attorneys shall be conclusive evidence
of such good faith.

     (c) You are hereby expressly authorized to disregard any and all warnings
given by any of the parties hereto or by any other person or Company, excepting
only orders or process of courts of law, and are hereby expressly authorized to
comply with and obey orders, judgments or decrees of any court.  In case you
obey or comply with any such order, judgment or decree of any court, you shall
not be liable to any of the parties hereto or to any other person, firm or
Company by reason of such compliance, notwithstanding any such order, judgment
or decree being subsequently reversed, modified, annulled, set aside, vacated or
found to have been entered without jurisdiction.

     (d) You shall not be liable in any respect on account of the identity,
authority or rights of the parties executing or delivering or purporting to
execute or deliver the Agreement or any documents or papers deposited or called
for hereunder.

     (e) You shall be entitled to employ such legal counsel and other experts as
you may deem necessary properly to advise you in connection with your
obligations hereunder and may reply upon the advice of such counsel.
<PAGE>

     (f) Your rights and responsibilities as Escrow Agent hereunder shall
terminate if (i) you cease to be Clerk of the Company or (ii) you resign by
written notice to each party.  In the event of a termination under clause (i),
your successor as Clerk shall become Escrow Agent hereunder; in the event of a
termination under clause (ii), the Company shall appoint a successor Escrow
Agent hereunder.

     (g) If you reasonably require other or further instruments in connection
with these Joint Escrow Instructions or obligations in respect hereto, the
necessary parties hereto shall join in furnishing such instruments.

     (h) It is understood and agreed that should any dispute arise with respect
to the delivery and/or ownership or right of possession of the securities held
by you hereunder, you are authorized and directed to retain in your possession
without liability to anyone all or any part of said securities until such
dispute shall have been settled either by mutual written agreement of the
parties concerned or by a final order, decree or judgment of a court of
competent jurisdiction after the time for appeal has expired and no appeal has
been perfected, but you shall be under no duty whatsoever to institute or defend
any such proceedings.

     (i) These Joint Escrow Instructions set forth your sole duties with respect
to any and all matters pertinent hereto and no implied duties or obligations
shall be read into these Joint Escrow Instructions against you.

     (j) The Company shall indemnify you and hold you harmless against any and
all damages, losses, liabilities, costs, and expenses, including attorneys' fees
and disbursements, for anything done or omitted to be done by you as Escrow
Agent in connection with this Agreement or the performance of your duties
hereunder, except such as shall result from your gross negligence or willful
misconduct.

     5. Notice
        ------

       All notices, instructions, and other communications given hereunder or in
connection herewith shall be in writing.  Any such notice, instruction or
communication shall be sent to each of the other parties thereunto entitled
either (i) by registered or certified mail, return receipt requested, postage
prepaid, or (ii) prepaid via a reputable nationwide overnight courier service,
in each case addressed to the Company at Vice President, Human Resources, Banyan
Systems Incorporated, 120 Flanders Road, P.O. Box 5013, Westboro, Massachusetts
01581-5013, to the Participant at 30 Partridge Lane, Boxford, MA 01921 and to
you at Clerk, Banyan Systems Incorporated, 120 Flanders Road, P.O. Box 5013,
Westboro, Massachusetts 01581-5013 (or to such other address as a party may have
furnished to the other parties in writing in accordance herewith).  Any such
notice, instruction or communication shall be deemed to have been delivered five
business days after it is sent by registered or certified mail, return receipt
requested, postage prepaid, or one business day after it is sent via a reputable
nationwide overnight courier service.  Any party may give any notice,
instruction or other communication hereunder using any other means, but no such
notice, instruction or other communication shall be deemed to have been duly
delivered unless and until it actually is received by the party for whom it is
intended.
<PAGE>

     6. Miscellaneous
        -------------

       (a) By signing these Joint Escrow Instructions, you become a party hereto
only for the purpose of said Joint Escrow Instructions, and you do not become a
party to the Agreement.

       (b) This instrument shall be binding upon and inure to the benefit of the
  parties hereto and their respective successors and permitted assigns.

                                 Very Truly Yours,

                                 BANYAN SYSTEMS INCORPORATED

                                 By:    /s/ William P. Ferry
                                     -------------------------------------
                                 Name: William P. Ferry
                                 Title:   Chairman and
                                 Chief Executive Officer

                                 HOLDER

                                    /s/ Scott G. Silk
                                 ----------------------------------------
                                 Name: Scott G. Silk


ESCROW AGENT

  /s/ Richard M. Spaulding
-----------------------------------
Name: Richard M. Spaulding
Title:  Clerk