I've lost the Administrator logon password for my Windows NT 4.0 server. How can I recover the password without reinstalling NT?
I've answered this question before, but it's a crucial problem that we can all face at some point. Fortunately, several solutions are available to help you recover or reset a system's Administrator password without reinstalling the OS. You can use a password-cracking tool such as @stake's LC 5 (formerly L0phtCrack—http://www.atstake.com/products/lc) to recover a lost password, although if a password is properly constructed according to complex password requirements, a password-cracking tool likely won't work. To learn more about complex password requirements, see "Creating a Strong Password Policy" (http://www.microsoft.com/technet/prodtechnol/windowsserver2003/library/DepKit/041728b4-5ed9-44a8-99fe-c050333d4245.mspx). You can also use a utility that lets you boot to a recovery disk, then reset the account password. Two such tools are the Offline NT Password & Registry Editor (http://home.eunet.no/~pnordahl/ntpasswd/editor.html), which lets you boot to a 3.5" disk, and Emergency Boot CD (EBCD—http://ebcd.pcministry.com), which lets you boot to a CD-ROM. Both are free utilities, and both boot into a Linux kernel, let you enter a new password, then change the appropriate SAM in the registry. All these tools will run on NT and later systems.
—Bob Chronister