You say.. you forgot your Windows administrator’s password,it doesn’t really matter. The fact is that you need to gain access to a computer and you cannot “remember” the administrator’s password.
One method is by trying to restore a backed up System State (in Windows 2000/XP/2003) or a ERD (in NT 4.0) in which you do remember the password.
Second method might be to install a parallel operating system on a different partition on the same computer, then use a simple trick to gain access to the old system.
Freeware Password Recovery Tools
Note :- Before trying any of these tools resetting a user’s or administrator’s password on some systems might cause data loss, especially EFS-encrypted files and saved passwords from within Internet Explorer. To protect yourself against EFS-encrypted files loss you should always export your Private and Public key, along with the keys for the Recovery Agent user.
Windows Password recovery
Login Recovery is a service to reveal user names and recover passwords for Windows NT, 2000, XP, 2003 and Vista. As long as you have physical access to the computer, your passwords can be recovered
Download This tool from here
Petter Nordahl-Hagen’s Offline NT Password & Registry Editor
This tool will support Vista/2003/XP/2000/NT
This is a utility to (re)set the password of any user that has a valid (local) account on your NT system.
You do not need to know the old password to set a new one.
It works offline, that is, you have to shutdown your computer and boot off a floppydisk or CD.
Will detect and offer to unlock locked or disabled out user accounts!
It is also an almost fully functional registry editor!
Download This tool from here
Openwall’s John the Ripper
John the Ripper is a fast password cracker, currently available for many flavors of Unix (11 are officially supported, not counting different architectures), Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. Besides several crypt(3) password hash types most commonly found on various Unix flavors, supported out of the box are Kerberos AFS and Windows NT/2000/XP/2003 LM hashes, plus several more with contributed patches.
Download this tool from here
EBCD – Emergency Boot CD
EBCD is a bootable CD, intended for system recovery in the case of software or hardware faults. It is able to create backup copies of normally working system and restore system to saved state. It contains the best system software ever created, properly compiled and configured for the maximum efficient use.
You may download image builder utility which creates image of bootable CD-ROM (.ISO file), plus basic set of system tools. When the image is ready, write it to CD-R or CD-RW, and then everytime you’ll need convenient and powerful system tools they’ll be just at hand.
It is easy to customize the disk for your needs. You can include to CD any program you like, or remake the structure of CD completely. All you need is to change a few lines in configuration XML files.
Download this CD from here