Password-reset disk only works with the same computer which you created on. To unlock the account, you can use PCUnlocker Live CD, Offline NT Password & Registry Editor, Kon-Boot or Ophcrack Live CD.
If you have a Windows install media, just boot with it and you can wipe the data/partition and...
Windows.old is the backup of your previous Windows installation, and it could be used to roll back to your previous OS. For privacy concern, the Windows.old file should be deleted before selling the PC. But you need to take ownership of Windows.old folder before deleting it, and this can be done...
@Xdqwerty good. thats great fma takes more time to to build up the beginning. brotherhood rushed the beginnign because the beginning had already been told