If you have forgotten your WINDOWS password, you should, in most cases be able to either recover or remove the password.
Before you try one of the methods below, there may be an easy way to find or reset your passwords, This method was pointed out to me by another Expert on this site ratz01
1. First reboot Windows XP in safe mode by re-starting the computer and pressing F8 repeated as the computer starts up. IF it still asks you for a password in safe mode, type ctrl+Alt+delete and try log in as Administrator
2. Then (in safe mode) click Start and then click Run. In the open box type "control userpasswords2" (without the quotes, of course)
3. You will now have access to all the user accounts, including the administrators account and will be able to reset the lost password.
4. Just click the administrators user account (or the target user's account), and then click Reset Password. You will need to add a new password in the New password and the Confirm new password boxes, and confirm by clicking OK.
5. All done, you have recovered the lost password ;-) If this method wont work for you, try these other methods
You need to make a BOOTABLE CD from a downloaded ISO file.
You will need an image burning program, I use IMGBURN, its free and small.
Download the file and burn the image.
Put the CD in the drive and boot your PC/Laptop ( you may need to enter the bios and set the CD/DVD drive as your 1st boot device.
Use OPHCRACK To RECOVER the password. download here.. (XP and Vista Versions)http://pcsupport.about.com/gi/o.htm?zi=1/XJ&zTi=1&sdn=pcsupport&cdn=compute&tm=8&gps=514_330_1276_818&f=00&su=p284.9.336.ip_p504.1.336.ip_&tt=4&bt=0&bts=1&zu=http%3A//ophcrack.sourceforge.net/
Use Offline NT Password & Registry Editor to REMOVE the password, download here.. http://pcsupport.about.com/gi/o.htm?zi=1/XJ&zTi=1&sdn=pcsupport&cdn=compute&tm=11&gps=525_323_1276_818&f=00&su=p284.9.336.ip_p504.1.336.ip_&tt=4&bt=1&bts=1&zu=http%3A//pogostick.net/%7Epnh/ntpasswd/bootdisk.html