Question Troubles with PC locking up

[generaljohn]

One of my friends is having issues with his old gaming PC, he says that it keeps locking up to the point where nothing responds and he has to hard reboot. What I thought was weird was he said that if he hasn't used his PC in a while he can use it for 10 minutes then after that it freezes, it gets worse and worse to the point to where he can't even get windows to load his desktop before it freezes up. To me it sounds like the PC might be over heating, but what's strange is that he's not blue screening. Any ideas, or things I should test when I go over to take a look at it?

 

[generaljohn]

Backing up your system is necessary but can download free or paid tools to back up.

are you suggesting that I should try reinstalling windows?