I guess I will give you the benefit of the doubt or at least throw this comment out here for others as a security precaution, if your box is windows XP Home Edition, then microsoft made a huge security mistake by not making the administrator account easily accessible to ppl who dont know what they are doing, given it means you arent using the primary windows account but at the same time you dont password protect it.

So next time you reboot your computer push f8 over and over until you get a chance that a screen will pop up, start your computer in safe mode, then login with the administrator account, no password should be necessary. Now you should be able to go to control panels and go into the user accounts section and you should be able to change your password back again. or delete and recreate you account. hope this helps you or someone. Remember those of you who didnt know to go in there and set a password on your admin account.. just a little bit more security