http://support.microsoft.com/default.aspx/kb/933168
Hopefully the above link will help. It is about restoring to previous OS
after installing Vista
"MadJrFlorida" wrote:
> I purchased a Dell (with a wireless keyboard) about a year ago with Windows
> XP installed. I upgraded to Vista, but it has too many bugs for me and none
> of my games work smoothly anymore, but when I try to re-install XP, it says
> it's "blocked" and it wont let me because I have a newer OS installed. So I
> tried to go into the boot menu to format my HD or maybe try to install it the
> old fashioned way, but since I have a wireless keyboard which hooks into the
> USB, it won't work because it doesn't get recognized until half way into the
> booting process. If anybody can help, that would be great. Vista is good,
> but still has too many bugs.