The passwords arent stored in plain text like they are in say, 98. You have very limited options if you have forgotten all the admin passwords.
You could download a version of L0pht Crack and run it on your XP install. Point it to the 2k SAM ( file where the passwords are stored).
It will use a dictionary and then brute Force to try and crack the passwords. If you know your password was an english word found in the dictionary, then you may be ok. If it wasnt and/or had numbers and/or non alpha characters in it, you could be in serious trouble, as this could take days, even weeks to brute force.
The really crappy part about all this is that you will most likely never get in to your 2k install again. The time it takes to brute force a password often makes a re-install a more attractive option.