I have a PC built in 2008. My last one with win7. It now shuts down without warning after a few minutes being on. I tried re-installing win7 and it shut off during the install. Also tried a Linux install and the same thing happened. When in the BIOS it stays on forever. It's so old it's almost not worth spending time or money on, but I am wondering if you have thoughts on some easy things to try.