Using same password for many computer isn’t save but remembering too many password can be lead to disaster. Can’t login to our desktop

Some utility that exist on internet that might be helpfull to help you to recover your windows xp password or create a new one :

• Offline NT Password & Registry Editor, Bootdisk / CD : edit the passwords on most systems.
• Offline NT/Win2K,XP,Vista password editor : this is a utility to (re)set the password of any user that has a valid (local) account on your NT system, by modifying  the crypted password in the registrys SAM file.
• L0phtCrack :  The integrated password cracker for NT
• Ultimate Boot CD : bootable CD that contains nt/2000/xp password changer

But the only tool that I every try myself is 0phrack, follow this guide carefully and I can see my password