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                                                                   EXHIBIT 10.33


                                 PROMISSORY NOTE

$3,000,000.00                                                   October 31, 2000

         FOR VALUED RECEIVED, the undersigned, ISN Software Corporation, a
Delaware corporation ("Borrower"), unconditionally promises to pay to the order
of EarthCare Company, a Delaware corporation ("Lender"), in Dallas, Texas, the
principal sum of THREE MILLION AND NO/100 DOLLARS ($3,000,000.00), in lawful
money of the United States and in immediately available funds; provided,
however, that in the event Lender does not continue actively to use the OS2K
software in its business operations through December 31, 2001, then the
principal amount of this Note shall automatically be reduced by $1,000,000. The
outstanding principal amount of this Promissory Note shall bear interest at a
rate of ten percent (10%) per annum; provided, however, that after default or
maturity, principal and past-due interest shall bear interest at the lesser of
18% or the highest lawful rate (the "Maximum Rate").

         Payments of principal and accrued interest on this Promissory Note
(this "Note") shall be paid in kind, and made (i) on the 15th of each month in
amounts equal to ten percent (10%) of the Gross Revenue of Borrower for the
immediately preceding calendar month, (ii) within ten (10) business days
following receipt by Borrower of payments of equity capital after the date
hereof in excess of $500,000, on a cumulative basis, an amount equal to
twenty-five percent (25%) of such excess equity capital, and (iii) within ten
(10) business days following receipt by Borrower of cash or other liquid
proceeds from the sale of substantially all of its assets. In no event shall
payments of principal or accrued interest be required except as specifically set
forth in the immediately preceding sentence. The term "Gross Revenue" shall mean
actual cash receipts of Borrower, less the following amounts: (a) any cash,
trade or promotional discounts; (b) sales or use taxes, excise taxes, and
value-added taxes for licensing (where applicable); (c) duties; (d) returns,
including a reserve for future returns; (e) price protection allowances; and (f)
any insurance, packing or shipping charges, to the extent the same are actually
included in the invoice price.

         Any amounts payable under this Note may be offset against certain
damages claimed by Borrower pursuant to Section 7.5 of that certain Asset
Purchase Agreement, effective as of October 31, 2000, by and between Borrower
and Lender.

         Any amounts payable under this Note may be prepaid, in whole or in
part, at any time without penalty or fee of any kind. Failure to accelerate
maturity or to exercise any right or remedy shall not preclude the acceleration
of maturity or the exercise of any right or remedy in case of one or more
subsequent defaults.

         Borrower and all parties now or hereafter liable for the payment
hereof, whether as endorser, guarantor, surety or otherwise, severally waive
demand, presentment for payment, notice of dishonor, notice of intention to
demand or accelerate payment hereof, protest and notice of protest, and
diligence in collecting or bringing suit against any party hereof, and agree to
all



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extensions, renewals, indulgences, releases or changes which from time to time
may be granted by the holder hereof and to all partial payments hereon, with or
without notice, before or after maturity.

         Interest paid or agreed to be paid shall not exceed the maximum amount
permissible under the applicable laws of the United States or the State of
Texas, and, in any contingency whatsoever, if Lender shall receive anything of
value deemed interest under such laws which would exceed the amount of interest
permissible under those laws, the excessive interest shall be applied first to
the reduction of unpaid principal under this Note and the remainder of such
excessive interest shall then be refunded to Borrower if such excessive interest
exceeds unpaid principal. All interest paid or agreed to be paid under this Note
shall, to the extent permitted by applicable law, be amortized, prorated,
allocated and spread throughout the full period until payment in full of the
principal (including the period of any renewal or extension hereof) so that the
interest hereon for such full period shall not exceed the Maximum Rate.

         If this Note is placed in the hands of an attorney for collection, or
if it is collected through bankruptcy or other judicial proceedings, Borrower
further agrees to pay all expenses of collection, including, without limitation,
attorneys' fees, incurred by the holder hereof.

         THIS NOTE SHALL BE GOVERNED BY AND CONSTRUED AND ENFORCED IN ACCORDANCE
WITH THE SUBSTANTIVE LAWS OF THE STATE OF TEXAS AND THE LAWS OF THE UNITED
STATES APPLICABLE TO TRANSACTIONS IN TEXAS, WITHOUT REGARD TO ITS PRINCIPLES OF
CONFLICTS OF LAWS.

                                                    BORROWER:

                                                    ISN Software Corporation


                                                    By:
                                                       -------------------------
                                                       William Addy, President