Problem getting my windows xp back


I posted this in the Windows Legacy section....but I think i was suppose to post it here so sorry for double posting....

I had Windows XP MCE. I decided to upgrade to Windows Vista just to try it out... I was having to many problems with the software I chose to use and stuff. So I want to reverse the process as in... remove vista and go back to my original OS with my files.. I backed up everything so everything is in windows.old folder. When I start up my comp. I get 2 options. Earlier Version of Windows, and Microsoft Windows Vista. I go into Earlier Version of Windows im getting to recover it. I get 3 notices again. Select which drive to recover (something like that) I select my C drive. After that it prompts me for a Administrator Passowrd. I stress this very much... I have never set a password on my computer ever... I bought it and started using it. I always logged in as Administrator in WinXP no password since I am the only one that uses it. I tried so many different combinations. After 3 tries, it restarts my computer. Can anyone help me?
Hi kurogen, welcome to NST.
Does Vista system restore have a restore point set at upgrade to revert back to XP?
Or add/remove programs have an uninstall Vista option ?
I didn't upgrade to Vista, I installed it on a brand new build PC, so I don't have practical experience, but when I upgraded ME to XP, it left a Windows.Old folder, with one or other of those options available for a month or so.