|If you can login in "safe mode with mode command prompt", you may be able to access the hidden admin account, but sometimes it tells you your account does not have privileges to run the command, but if you need your stuff it's worth a try. Turn on computer and tap F8 a few times, brings up a menu, select safe mode with command prompt.|
When you get to the black screen with command prompt. type the following command, noting the space after administrator.
net user administrator /active:yes hit enter key. If this completes successfully, then reboot and Vista loads up it will now show your old account and the admin account, click the admin account and login. That will give you access to your user files. To hide the admin account you would run the command prompt again and type
net user administrator /active:no hit enter.