1. Boot from the Windows Installation/Recovery CD
2. When you get to the Version Selection Screen choose the repair this computer link at the bottom
3. From the repair menu choose to open a command prompt.
4. Move the sticky keys application by running the following from the command prompt.
copy c:\Windows\System32\sethc.exe c:\Windows\System32\sethc.exe.moved
5. Replace the stuck key application by running the following:
copy c:\Windows\System32\cmd.exe d:\Windows\System32\sethc.exe
6. Reboot the machine
7. When the system boots up to a login screen hold down a nonfunctional key like space or shift for 6 seconds or press it rapidly to trigger the sticky keys dialog. The sticky keys dialog will have been replaced with a command prompt that will open with elevated privileges.
8. You now have a mounted file system and a Administrator command prompt, reset the password with the following command replacing 'NewPassword' with your desired password and the user 'Administrator' with the desired user.
net user Administrator NewPassword
9. Your password has now been reset, restart the system.
10. Don't forget to unhack your machine, leaving it with the sethc.exe replaced present a clear security issue, you'll want to just revert the files you renamed and can do so with the following command executed in an elevated command prompt.
del c:\Windows\System32\sethc.exe move c:\windows\System32\sethc.exe.moved c:\Windows\System32\sethc.exe