This forum is closed. Thank you for your contributions.
Hi,
You could try booting up your computer pushing up F8 to boot on safe mode and open administrator account if you have it.
If you don't have, you could use tome third tools to clear it for exemple in Hiren's boot cd you can find some utilities.
If you want to do it manually, you can use this tutorial :
http://www.computernetworkingnotes.com/window-7-tips-and-tricks/how-to-reset-window-7-administrator-password.html