<PAGE>

                                                                    EXHIBIT 4.10

THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED
(THE "ACT"), AND MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF AN EFFECTIVE
REGISTRATION STATEMENT UNDER THE ACT OR AN EXEMPTION FROM REGISTRATION
THEREUNDER.


                                PROMISSORY NOTE
                                      OF
                             XCEL MANAGEMENT, INC.
                                                              Tacoma, Washington
$127,500.00                                                        July 17, 2000

          FOR VALUE RECEIVED, Xcel Management, Inc., a Utah corporation
(including any successor or assign thereof, including, without limitation, a
receiver, trustee or debtor-in-possession, "Maker"), hereby promises to pay to
                                            -----
the order of Garnier Holdings, Ltd. ("Payee") the sum of ONE HUNDRED TWENTY
                                      -----
SEVEN THOUSAND FIVE HUNDRED DOLLARS AND 00/CENTS ($127,500.00) on the date set
forth below.

          1.  Payment of Principal.  The amount of this Note, together with all
              --------------------
interest accrued hereon, shall be due and payable on August 17, 2000 (the

"Maturity Date").
--------------

          2.  Payment of Interest.  Interest shall be compounded annually at the
              -------------------
Chase Manhattan Bank, N.A. rate quoted as its prime rate.

          3.  Terms of Payment.  Subject to prepayments made pursuant to Section
              ----------------
6 hereunder, the amount of ONE HUNDRED TWENTY SEVEN THOUSAND FIVE HUNDRED
DOLLARS AND 00/CENTS ($127,500.00) shall become due and payable on the Maturity
Date.  This amount consists of the principal amount plus the compounded interest
accrued from the date hereon up to and including the Maturity Date.

          4.  Prepayment.  Maker may, at its option at any time and from time to
              ----------
time hereafter, prepay, in whole or in part, without premium or penalty, the
outstanding principal amount of this Note, together with accrued but unpaid
interest on such principal amount to the date of prepayment.

          5.  Assignability; Transferrability.
              -------------------------------

          (a)  This Note is freely transferrable and assignable by Payee, and
does not require the consent of Maker, only where the Note is assigned to a
family member or affiliate of Payee without payment of consideration.

                                      -1-
<PAGE>

          (b) Any other transfer or assignment must be with the consent of
Maker and pursuant to an exemption under the Securities Act of 1933, as amended,
and state blue sky regulations, if applicable.

          6.  Defaults; Consequences of Default.
              ---------------------------------

          (a) Defaults.  Maker shall be deemed in default hereunder upon the
              --------
occurrence of any of the following (a "Default"):
                                       -------

              (i)   Failure to Pay Principal or Interest:  The failure of Maker
                    ------------------------------------
     to pay, when due, all or any part of any principal, interest or other
     payment required to be made hereunder and continuance of such failure for
     thirty (30) business days after written notice thereof to Maker from Payee;

              (ii)  Failure to Perform Other Provisions:  Maker fails to perform
                    -----------------------------------
     or observe any other provision contained herein and continuance of such
     failure for thirty (30) business days after written notice thereof to Maker
     from Payee; or

              (iii) Bankruptcy, etc.:  Maker has entered against it by a court
                    ----------------
     having jurisdiction thereof a decree or order for relief in respect to
     Maker in an involuntary case under any applicable bankruptcy, insolvency or
     other similar law now or hereafter in effect, or a receiver, liquidator,
     assignee, custodian, trustee or other similar official is appointed for
     Maker or for any substantial part of Maker's property, or the winding up or
     liquidation of Maker's affairs is ordered; or Maker commences a voluntary
     case under any applicable bankruptcy, insolvency or other similar law now
     or hereafter in effect, or consents to the entry of an order for such
     relief in an involuntary case under any such law, or any such involuntary
     case is commenced and is not dismissed within sixty (60) days, or Maker
     consents to the appointment of or taking possession by a receiver,
     liquidator, assignee, custodian, trustee or other similar official for
     Maker or for any substantial part of Maker's property, or makes any general
     assignment for the benefit of creditors.

          (b) Consequences of Default.  Upon the occurrence of a Default of the
              -----------------------
type described in Section 8(a) above, the aggregate principal amount of the Note
(together with all accrued interest thereon and all other amounts payable in
connection therewith) shall become immediately due and payable without any
action on the part of the holder of the Note.

                                      -2-
<PAGE>

          7.  Miscellaneous.
              -------------

          (a) Principal and interest due hereunder shall be payable in lawful
money of the United States of America and shall be payable to Payee at the
principal offices of Maker, or at such other address as may be specified in a
written notice to Maker given by Payee.

          (b) If any payment on this Note shall become due on a day which is not
a Business Day, such payment shall be made on the next succeeding Business Day,
and such extension of time shall in such case be included in computing interest
in connection with payment.  The term "Business Day" as used herein means any
                                       ------------
day other than Saturday or Sunday or a public holiday under the laws of the
State of Washington or other day on which banking institutions are authorized or
obligated to close in the City of Tacoma in the State of Washington as of the
date of determination.

          (c) No delay or omission on the part of Payee in the exercise of any
right or remedy hereunder shall operate as a waiver thereof and no partial
exercise of any right or remedy precludes other or further exercise thereof or
the exercise of any other rights or remedy.

          (d) Maker agrees to pay on demand all reasonable costs and expenses,
including reasonable attorneys' fees, incurred by Payee in enforcing this Note.

          (e) Maker hereby waives presentment, protest and demand, notice of
protest, demand and dishonor and nonpayment of this Note.

          (f) Anything in this Note to the contrary notwithstanding, this Note
shall be binding on any successors and assigns of the holder of this Note and
Maker.

          (g) Anything in this Note to the contrary notwithstanding, payments
under this Note shall not be deferred beyond any date if deferral beyond such
date would result in this Note (or any note in respect of which, directly or
indirectly, this Note was issued) being treated as an "applicable high yield
                                                       ---------------------
discount obligation" under Section 163(e)(5) and Section 163(i) of the Internal
-------------------
Revenue Code of 1986, as amended (the "Code").  The preceding sentence shall
                                       ----
apply only to the extent necessary to achieve the objective herein described and
shall apply only to amounts treated as interest or original issue discount under
the Code.

          (h) Upon receipt of evidence reasonably satisfactory to the Maker of
the mutilation, destruction, loss or theft of the Note and the ownership
thereof, and, in the case of any such mutilation, upon surrender and
cancellation of this Note, the Maker shall, upon the written request of the
holder of the Note, execute and deliver in replacement thereof a new Note in the
same form, in the same original principal amount and dated the same date as the
Note so mutilated, destroyed, lost or stolen, and such Note so mutilated,
destroyed, lost or stolen shall

                                      -3-
<PAGE>

then be deemed no longer outstanding hereunder.

          (i) Except as otherwise expressly provided herein, the provisions of
the Note may be amended and Maker may take any action herein prohibited, or omit
to perform any act herein required to be performed by it, only if Maker has
obtained the written consent of the holder (plus all accrued but unpaid
interest) of the Note then outstanding; provided that without the written
                                        --------
consent of the holder of the Note no such action shall (i) reduce the rate at
which or change the manner in which interest accrues on the Note or the times at
which such interest becomes payable, or (ii) change any provision relating to
the scheduled payments or prepayments of principal on the Note.

          (j) No remedy herein conferred upon the holder of this Note is
intended to be exclusive of any other remedy, and each and every such remedy
shall be cumulative and shall be in addition to every other remedy given
hereunder or now or hereafter existing at law or in equity or by statute or
otherwise.

          (k) It is the intention of Maker and the holder of this Note to
conform to all applicable usury laws now and hereafter in force, and any
interest payable under this Note shall be subject to reduction to the amount not
in excess of the maximum legal amount allowed under the applicable usury laws as
now or hereafter construed by the courts having jurisdiction over such matters.
If the maturity of this Note is accelerated by reason of an election by the
holder hereof resulting from an occurrence of Default, voluntary prepayment by
Maker or otherwise, then earned interest may never include more than the maximum
amount permitted by law, computed from the date hereof until payment, and any
interest in excess of the maximum amount permitted by law shall be canceled
automatically and, if theretofore paid, shall at the option of the holder hereof
either be rebated to Maker or credited on the principal amount of this Note, or
if this Note has been paid, then the excess shall be rebated to Maker.  The
aggregate of all interest (whether designated as interest, service charges,
points or otherwise) contracted for, chargeable or receivable under this Note
shall under no circumstances exceed the maximum legal rate upon the unpaid
principal balance of this Note remaining unpaid from time to time.  If such
interest does exceed the maximum legal rate, it shall be canceled automatically
and, if theretofore paid, rebated to Maker or credited on the principal amount
of this Note, or if this Note has been repaid, then such excess shall be rebated
to Maker.

          This Note shall be governed by and construed in accordance with the
domestic laws of the State of Washington, without giving effect to any choice of
law or conflict of law provision or rule (whether of the State of Washington or
any other jurisdiction) that would cause the application of the laws of any
jurisdiction other than the State of Washington.


                           *     *     *     *     *

                                      -4-
<PAGE>

          IN WITNESS WHEREOF, Maker has executed and delivered this Note on the
date first above written.



                              XCEL  MANAGEMENT, INC.


                              By: __________________________________

                              Its:  ________________________________

                                      -5-
<PAGE>

                         Extension of Promissory Note

     This Extension of Promissory Note (this "Extension") is effective as of
September 11, 2000, by and between InsynQ, Inc., a Delaware corporation
(formerly Xcel Management, Inc.) (the "Maker"), and Garnier Holdings, Ltd.
("Payee").

                                   WITNESSETH

     WHEREAS, the parties have executed that certain Promissory Note as of July
17, 2000; and

     WHEREAS, the parties have deemed it to be in their mutual best interest to
extend the Maturity Date of the Promissory Note to reflect a new Maturity Date
of October 1, 2000.

     NOW, THEREFORE, in consideration of the foregoing, and of the mutual
covenants hereinafter contained, and of other good and valuable consideration,
the receipt and sufficiency of which are hereby acknowledged, the parties hereto
agree as follows:

     The Promissory Note is hereby amended to reflect a new Maturity Date of
October 1, 2000, without prejudice to the Payee's right to reduce the exercise
price of Payee's Warrants issued on the same date as the Promissory Note, based
on the previous Maturity Date of August 17, 2000, as long as the principal
amount under the Promissory Note remains unpaid.

     IN WITNESS WHEREOF, the parties have executed this Extension effective as
of the date set forth above.


                                     GARNIER HOLDINGS, LTD.


                                     By:
                                        ---------------------------------------
                                     Name:
                                          -------------------------------------
                                     Title:
                                           ------------------------------------


                                     INSYNQ, INC.


                                     By:
                                        ---------------------------------------
                                     Name:
                                          -------------------------------------
                                     Title:
                                           ------------------------------------