command: net user [username] [password]
here's a method that works
boot the computer into a mode that gives you access to the command prompt. if you use a windows installer, select the repair computer option
a the command prompt, change directory to c:\windows\system32
copy “cmd.exe” to replace “utilman.exe” using the following commands:
move utilman.exe utilman.bak
copy cmd.exe utilman.exe
reboot the computer
boot the computer in normal mode, at the windows login screen use crtl+alt+del to open the windows login dialog, then use windowskey+u and the command prompt should open
in the command prompt window type the following command:
net user [username] [password]
make [username] the name of the administrator account, and [password] will be your new password
close the command prompt window and login with your new password
