ok, still as clear as mud what you are asking for.
let's try a few questions...
do you have a laptop or desktop PC?
where did you get those voltage readings from?
how old is the PC?
do you get any error messages?
what is the version of Windows?
basically it sounds like your PC is randomly shutting down (for whatever reason), a common reason is dust build-up, have you blown out any excessive dust within the chassis?
have you tested the memory?
remember - better info means better advice.