computer keeps restarting!

[GTTKC]

i have a 2nd computer that i use, its my dads(he just passed away) do i got his computer

he had a trial version of windows 7 on it, and before that had vista. well the trial verson is up now and it always has a pop up saying i need to upgrade. well now my computer keeps restarting every 5-10 minutes. no matter what i do it keeps restarting, does anyone know whats going on?

please help!

Thanks

 

[Dystopia]

That's probably because you have the trial version, so Win7 is automatically restarting. If you can, install Vista on it again, or any other operating system, and see if it still gives you trouble.

 

[GTTKC]

well i have windows vista still on it, and had a trial version on windows 7, but the trial ran out so now im running windows vista still on it, could that still be the cause?