<PAGE>
                                                                    EXHIBIT 10.4

                                HOLDINGS GUARANTY

      This Guaranty (this "GUARANTY") is dated as of September 30, 2004 by
COMSYS HOLDING, INC., a Delaware corporation ("COMSYS HOLDINGS"), COMSYS IT
Partners, Inc., a Delaware corporation ("HOLDINGS"), and PFI Corp., a Delaware
corporation ("PFI HOLDINGS"; PFI Holdings together with Holdings and COMSYS
Holdings are sometimes referred to hereinafter individually as a "GUARANTOR" and
collectively as the "GUARANTORS"), in favor of HERITAGE BANK, SSB, a
Texas-Chartered Bank, in its capacity as Collateral Agent under the Credit
Agreement described below (the "COLLATERAL AGENT"), and MERRILL LYNCH CAPITAL, a
division of Merrill Lynch Business Financial Services Inc. ("ADMINISTRATIVE
AGENT; Administrative Agent and Collateral Agent are sometimes hereinafter
referred to individually as an "AGENT" and together as the "AGENTS").

                                   I. RECITALS

      Reference is made to that certain Term Loan Credit Agreement of even date
hereof (as the same may be amended, restated, modified or supplemented and in
effect from time to time, the "CREDIT AGREEMENT") by and among the Guarantors,
COMSYS Services LLC, a Delaware limited liability company ("COMSYS SERVICES"),
COMSYS Information Technology Services, Inc., a Delaware corporation ("COMSYS
IT"), Venturi Technology Partners, LLC, a North Carolina limited liability
company ("VTP"; VTP together with COMSYS Services and COMSYS IT are sometimes
referred to herein individually as a "BORROWER" and collectively as the
"BORROWERS"), COMSYS Services, in its capacity as borrowing agent and funds
administrator for the Borrowers, the Lenders from time to time party thereto,
Collateral Agent and Administrative Agent. As one of the conditions to making
Second Lien Term Loans (hereafter, the "LOANS") and other financial
accommodations available to Borrowers under the Credit Agreement, the Lenders
have required that each Guarantor guarantee the obligations of the Borrowers to
Agents and the Lenders. Capitalized terms used and not otherwise defined herein
shall have the respective meanings provided for in the Credit Agreement.

                                  II. GUARANTY

      Therefore, for value received, and in consideration of any loan, advance
or financial accommodation of any kind whatsoever heretofore, now or hereafter
made, given or granted to the Borrowers by either Agent or any Lender, each
Guarantor hereby unconditionally guarantees the full and prompt payment when
due, whether at maturity or earlier, by reason of acceleration or otherwise, and
at all times thereafter, of all of the Obligations. Without limiting the
foregoing, the Obligations guaranteed hereby include all fees, costs and
expenses (including attorneys' fees and expenses) incurred by either Agent or
any Lender in attempting to collect any amount due under this Guaranty or in
prosecuting any action against any Borrower, any Guarantor or any other
guarantor of all or part of the Obligations and all interest, fees, costs and
expenses owing to either Agent or any Lender after the commencement of
bankruptcy proceedings with respect to any Borrower, any Guarantor or any other
guarantor of all or part of the Obligations (whether or not the same may be
collected while such proceedings are pending).

      Each Guarantor hereby agrees that this Guaranty is a present and
continuing guaranty of payment and not of collection and that its obligations
hereunder shall be unconditional,

<PAGE>

irrespective of (i) the validity or enforceability of the Obligations or any
part thereof, or of any of the Financing Documents, (ii) the waiver or consent
by either Agent or any Lender with respect to any provision of any Financing
Document, or any amendment, modification or other change with respect to any
Financing Document, (iii) any merger or consolidation of any Borrower, any
Guarantor or any other guarantor of all or part of the Obligations into or with
any Person or any change in the ownership of the equity of any Borrower, any
Guarantor or any other guarantor of all or part of the Obligations, (iv) any
dissolution of any Guarantor or any insolvency, bankruptcy, liquidation,
reorganization or similar proceedings with respect to any Borrower, any
Guarantor or any other guarantor of all or part of the Obligations, (v) any
action or inaction on the part of either Agent or any Lender, including without
limitation the absence of any attempt to collect the Obligations from any
Borrower, any Guarantor or any other guarantor of all or part of the Obligations
or other action to enforce the same or the failure by Collateral Agent, on
behalf of the Agents and Lenders, to take any steps to perfect and maintain its
Lien on, or to preserve its rights to, any security or collateral for the
Obligations, (vi) either Agent's election, in any proceeding instituted under
Chapter 11 of Title 11 of the United States Code (11 U.S.C. Section 101 et
seq.), as amended (the "BANKRUPTCY CODE") of the application of Section
1111(b)(2) of the Bankruptcy Code, (vii) any borrowing or grant of a Lien by any
Borrower, any Guarantor or any other guarantor of all or part of the
Obligations, as debtor-in-possession, under Section 364 of the Bankruptcy Code,
(viii) the disallowance, under Section 502 of the Bankruptcy Code, of all or any
portion of either Agent's or any Lender's claims for repayment of the
Obligations, (ix) either Agent's or any Lender's inability to enforce the
Obligations of any Borrower as a result of the automatic stay provisions under
Section 362 of the Bankruptcy Code, (x) the discharge or release by either Agent
and/or Lenders of any Guarantor's obligations and liabilities under this
Guaranty, (xi) the discharge or release by either Agent and/or Lenders of any
other guarantor's obligations and liabilities under any guaranty or (xii) any
other circumstance which might otherwise constitute a legal or equitable
discharge or defense of any Borrower, any Guarantor or any other guarantor of
all or part of the Obligations other than a defense of payment and performance
in full in cash of all Obligations.

      Notwithstanding any provision of this Guaranty to the contrary, it is
intended that this Guaranty, and any Liens granted by any Guarantor to secure
the obligations and liabilities arising pursuant to this Guaranty, not
constitute a "FRAUDULENT CONVEYANCE" (as defined below). Consequently, each
Guarantor agrees that if this Guaranty, or any Liens securing the obligations
and liabilities arising pursuant to this Guaranty, would, but for the
application of this sentence, constitute a Fraudulent Conveyance, this Guaranty
and each such Lien shall be valid and enforceable only to the maximum extent
that would not cause this Guaranty or such Lien to constitute a Fraudulent
Conveyance, and this Guaranty shall automatically be deemed to have been amended
accordingly at all relevant times. For purposes hereof, "Fraudulent Conveyance"
means a fraudulent conveyance or fraudulent transfer under Section 548 of the
Bankruptcy Code or a fraudulent conveyance or fraudulent transfer under the
provisions of any applicable fraudulent conveyance or fraudulent transfer law or
similar law of any state, nation or other governmental unit, as in effect from
time to time.

      No payment made by or for the account or benefit of any Guarantor
(including, without limitation, (i) a payment made by any Borrower in respect of
the Obligations, (ii) a payment made by any Person under any other guaranty of
the Obligations or (iii) a payment made by

Holdings Guaranty (Term Loan)
60311480

                                       2
<PAGE>

means of set-off or other application of funds by either Agent or any Lender)
pursuant to this Guaranty shall entitle any Guarantor, by subrogation or
otherwise, to any payment by any Borrower or from or out of any property of any
Borrower, and no Guarantor shall exercise any right or remedy against any
Borrower or any property of any Borrower including, without limitation, any
right of contribution or reimbursement by reason of any performance by any
Guarantor under this Guaranty, until the Obligations have been indefeasibly paid
in full in cash and the Credit Agreement has been terminated; provided that, any
of the foregoing to the contrary notwithstanding, effective upon any sale,
registration, assignment or transfer of or foreclosure on, or any other
disposition or remedial action in respect of, any equity interests of any
Borrower or any other Subsidiary of any Guarantor or any Borrower by either
Agent or Lenders pursuant to the Financing Documents and/or applicable law, all
such rights and claims of subrogation, contribution, exoneration, reimbursement
and enforcement against the Borrowers and their Subsidiaries shall be, and
hereby are, forever extinguished and indefeasibly waived and released by each
Guarantor.

      Each Guarantor hereby waives diligence, presentment, demand of payment,
filing of claims with a court in the event of any bankruptcy proceeding (or
other insolvency proceeding) of any Borrower, protest or notice with respect to
the Obligations and all demands whatsoever, and covenants that this Guaranty
will not be discharged, except by complete and irrevocable payment and
performance of the obligations and liabilities contained herein. No notice to
the Guarantors or any other party shall be required for either Agent, on behalf
of Agents or any Lender, to make demand hereunder. Such demand shall constitute
a mature and liquidated claim against Guarantors. Upon the occurrence and during
the continuance of any Event of Default, either Agent may, at its sole election,
proceed directly and at once, without notice, against any Guarantor to collect
and recover the full amount or any portion of the Obligations, without first
proceeding against any Borrower, any other Guarantor, any other guarantor of the
Obligations, or any other Person or any security or collateral for the
Obligations. The Agents shall have the exclusive right to determine the
application of payments and credits, if any, from any Guarantor, any Borrower,
any other Person, or any security or collateral for the Obligations, on account
of the Obligations or of any other liability of any Guarantor to Agents and
Lenders arising hereunder.

      Agents and Lenders are hereby authorized, without notice or demand to any
Guarantor and without affecting or impairing the liability of any Guarantor
hereunder, to, from time to time, (i) renew, extend, accelerate or otherwise
change the time for payment of, or other terms relating to, the Obligations or
otherwise modify, amend or change the terms of any Financing Document, (ii)
accept partial payments on the Obligations, (iii) take and hold collateral for
the payment of the Obligations, or for the payment of this Guaranty, or for the
payment of any other guaranties of the Obligations or other liabilities of any
Borrower, and exchange, enforce, waive and release any such collateral, (iv)
apply such collateral and direct the order or manner of sale thereof as in their
sole discretion they may determine and (v) settle, release, compromise, collect
or otherwise liquidate the Obligations and any collateral therefor in any
manner.

      At any time after maturity of the Obligations, Agents and Lenders may, in
their sole discretion, without notice to any Guarantor and regardless of the
acceptance of any collateral for the payment hereof, appropriate and apply
toward payment of the Obligations (i) any

Holdings Guaranty (Term Loan)
60311480

                                       3

<PAGE>

indebtedness due or to become due from either Agent or any Lender to any
Guarantor and (ii) any moneys, credits or other property belonging to any
Guarantor at any time held by or coming into the possession of either Agent or
any Lender or any Affiliates thereof, whether for deposit or otherwise.

      Each Guarantor hereby assumes responsibility for keeping itself informed
of the financial condition of each Borrower, and any and all endorsers and other
guarantors of all or any part of the Obligations and of all other circumstances
bearing upon the risk of nonpayment of the Obligations or any part thereof that
diligent inquiry would reveal, and each Guarantor hereby agrees that no Agent
nor any Lender shall have any duty to advise any Guarantor of information known
to such Agent or Lender regarding such condition or any such circumstances. Each
Guarantor hereby acknowledges familiarity with each Borrower's financial
condition and that it has not relied on any statements by either Agent or any
Lender in obtaining such information. In the event either Agent or any Lender,
in its sole discretion, undertakes at any time or from time to time to provide
any such information to any Guarantor, no Agent nor any Lender shall be under
any obligation (i) to undertake any investigation with respect thereto, (ii) to
disclose any information which, pursuant to accepted or reasonable commercial
finance practices, such Agent or such Lender wishes to maintain confidential or
(iii) to make any other or future disclosures of such information, or any other
information, to such Guarantor.

      Each Guarantor consents and agrees that no Agent nor any Lender shall be
under any obligation to marshal any assets in favor of any Guarantor or against
or in payment of any or all of the Obligations. Each Guarantor further agrees
that, to the extent that any Borrower makes a payment or payments to either
Agent or any Lender, or either Agent or any Lender receives any proceeds of
Collateral, which payment or payments or any part thereof are subsequently
invalidated, declared to be fraudulent or preferential, set aside or required to
be repaid to any Borrower, its estate, trustee, receiver or any other party,
including without limitation any Guarantor, under any bankruptcy law, state or
federal law, common law or equitable cause, then to the extent of such payment
or repayment, the Obligations or the part thereof which has been paid, reduced
or satisfied by such amount shall be reinstated and continued in full force and
effect as of the date such initial payment, reduction or satisfaction occurred,
and this Guaranty shall continue to be in existence and in full force and
effect, irrespective of whether any evidence of indebtedness has been
surrendered or cancelled.

      Each Guarantor also waives all set-offs and counterclaims and all
presentments, demands for performance, notices of nonperformance, protests,
notices of protest, notices of dishonor, notices of acceleration, notices of
intent to accelerate and notices of acceptance of this Guaranty. Each Guarantor
further waives all notices of the existence, creation or incurring of new or
additional indebtedness, arising either from additional loans extended to any
Borrower or otherwise, and also waives all notices that the principal amount, or
any portion thereof, or any interest under or on any Financing Document is due,
notices of any and all proceedings to collect from the maker, any endorser or
any other guarantor of all or any part of the Obligations, or from anyone else,
and, to the extent permitted by law, notices of exchange, sale, surrender or
other handling of any security or collateral given to Collateral Agent to secure
payment of the Obligations.

Holdings Guaranty (Term Loan)
60311480

                                       4

<PAGE>

                       III. REPRESENTATIONS AND WARRANTIES

      Each Guarantor hereby represents and warrants to Agents and Lenders that
(i) it is duly organized, validly existing and in good standing under the laws
of the jurisdiction of its organization, (ii) the execution, delivery and
performance by such Guarantor of this Guaranty and the other Financing Documents
to which it is a party are within its powers, have been duly authorized by all
necessary action pursuant to its Organizational Documents, require no further
action by or in respect of, or filing with, any governmental body, agency or
official and do not violate, conflict with or cause a breach or a default under
any provision of applicable law or regulation, any of its Organizational
Documents or any agreement, judgment, injunction, order, decree or other
instrument binding upon it and (iii) this Guaranty, and each other Financing
Document to which it is a party, constitutes a valid and binding agreement or
instrument of such Guarantor, enforceable against such Guarantor in accordance
with its respective terms, except as the enforceability thereof may be limited
by bankruptcy, insolvency or other similar laws relating to the enforcement of
creditors' rights generally and by general equitable principles.

                                IV. MISCELLANEOUS

      No delay on the part of either Agent in the exercise of any right or
remedy shall operate as a waiver thereof, and no single or partial exercise by
either Agent of any right or remedy shall preclude any further exercise thereof;
nor shall any modification or waiver of any of the provisions of this Guaranty
be binding upon Agents or Lenders, except as expressly set forth in a writing
duly signed and delivered on Agents' behalf by an authorized officer or agent of
Agents. Agents' or any Lender's failure at any time or times hereafter to
require strict performance by Borrowers or Guarantors of any of the provisions,
warranties, terms and conditions contained in this Guaranty shall not waive,
affect or diminish any right of Agents and Lenders at any time or times
hereafter to demand strict performance thereof and such right shall not be
deemed to have been waived by any act or knowledge of either Agent or any
Lender, or its respective agents, officers or employees, unless such waiver is
contained in an instrument in writing signed by an officer or agent of such
Agent, and directed to Borrowers or Guarantors, as applicable, specifying such
waiver. No failure or delay by either Agent or any Lender in exercising any
right, power or privilege under this Guaranty shall operate as a waiver thereof
nor shall any single or partial exercise thereof preclude any other or further
exercise thereof or the exercise of any other right, power or privilege. The
rights and remedies herein provided shall be cumulative and not exclusive of any
rights or remedies provided by law. The obligations of each Guarantor under this
Guaranty are secured by, among other things, that certain Holdings Security
Agreement dated of even date herewith by and between each Guarantor and
Collateral Agent.

      This Guaranty shall be binding upon each Guarantor and its successors and
assigns and shall inure to the benefit of Agents and Lenders and their
respective successors and assigns, except that no Guarantor may assign its
obligations hereunder without the written consent of Agents.

      All notices, approvals, requests, demands and other communications
hereunder shall be given and deemed effective in accordance with the notice
provision of the Credit Agreement;

Holdings Guaranty (Term Loan)
60311480

                                       5

<PAGE>

provided, that such notices shall be given to each Guarantor at its address or
facsimile number set forth on the signature pages hereof.

      THIS GUARANTY SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF ILLINOIS, WITHOUT REGARD TO CONFLICTS
OF LAWS PRINCIPLES. EACH AGENT AND EACH GUARANTOR HEREBY CONSENT TO THE
JURISDICTION OF ANY STATE OR FEDERAL COURT LOCATED WITHIN THE COUNTY OF COOK,
STATE OF ILLINOIS AND IRREVOCABLY AGREE THAT, SUBJECT TO EITHER AGENT'S
ELECTION, ALL ACTIONS OR PROCEEDINGS ARISING OUT OF OR RELATING TO THIS GUARANTY
SHALL BE LITIGATED IN SUCH COURTS. EACH AGENT AND EACH GUARANTOR EXPRESSLY
SUBMIT AND CONSENT TO THE JURISDICTION OF THE AFORESAID COURTS AND WAIVE ANY
DEFENSE OF FORUM NON CONVENIENS. EACH AGENT AND EACH GUARANTOR HEREBY WAIVE
PERSONAL SERVICE OF ANY AND ALL PROCESS AND AGREE THAT ALL SUCH SERVICE OF
PROCESS MAY BE MADE UPON SUCH PARTY BY CERTIFIED OR REGISTERED MAIL, RETURN
RECEIPT REQUESTED, ADDRESSED TO SUCH PARTY IN ACCORDANCE WITH THE PROVISIONS OF
THE IMMEDIATE PRECEDING PARAGRAPH HEREOF AND SERVICE SO MADE SHALL BE DEEMED TO
BE COMPLETE TEN (10) DAYS AFTER THE SAME HAS BEEN POSTED.

      EACH GUARANTOR AND EACH AGENT HEREBY IRREVOCABLY WAIVE ANY AND ALL RIGHT
TO TRIAL BY JURY IN ANY LEGAL ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO
THIS AGREEMENT OR THE TRANSACTIONS CONTEMPLATED HEREBY AND AGREE THAT ANY SUCH
ACTION OR PROCEEDING SHALL BE TRIED BEFORE A COURT AND NOT BEFORE A JURY.

      This Guaranty may be signed in any number of counterparts, each of which
shall be an original, with the same effect as if the signatures thereto and
hereto were upon the same instrument.

      In addition to and without limitation of any of the foregoing, this
Guaranty shall be deemed to be a Financing Document and shall otherwise be
subject to all of general terms and conditions contained in Article 12 of the
Credit Agreement, mutatis mutandi.

      Administrative Agent, Collateral Agent, Lenders, First Lien Agent,
Borrowers and the Guarantors have entered into that certain Intercreditor and
Lien Subordination Agreement of even date hereof (as the same may be amended
from time to time pursuant to the terms thereof, the "SECOND LIEN INTERCREDITOR
AGREEMENT"). To the extent any provision of this Agreement conflicts with the
Second Lien Intercreditor Agreement, the Second Lien Intercreditor Agreement
shall control.

      [Remainder of Page Intentionally Left Blank; Signature Page Follows]

Holdings Guaranty (Term Loan)
60311480

                                       6

<PAGE>

      IN WITNESS WHEREOF, this Guaranty has been duly executed by the Guarantors
as of the date first written above.

                          GUARANTORS:

                          COMSYS HOLDING, INC., a Delaware corporation

                          By:    /s/ David L. Kerr
                          Name:  David L. Kerr
                          Title: Senior Vice President - Corporate Development

                          PFI CORP., a Delaware corporation

                          By:    /s/ David L. Kerr
                          Name:  David L. Kerr
                          Title: Senior Vice President - Corporate Development

                          COMSYS IT PARTNERS, INC., a Delaware corporation

                          By:    /s/ David L. Kerr
                          Name:  David L. Kerr
                          Title: Senior Vice President - Corporate Development

Holdings Guaranty (Term Loan)
60311480

<PAGE>

                                 AGENTS:

                                 MERRILL LYNCH CAPITAL, a division of Merrill
                                 Lynch Business Financial Services Inc., as
                                 Administrative Agent

                                 By:    /s/ Scott E. Gast
                                 Name:  Scott E. Gast
                                 Title: Vice President

                                 HERITAGE BANK, SSB, A TEXAS-CHARTERED BANK, as
                                 Collateral Agent

                                 By:    /s/ [illegible]
                                 Name:  ___________________________________
                                 Title: ___________________________________

Holdings Guaranty (Term Loan)
60311480

                                       2