This started happening a few years back with CSS and HL2, but today I finally decided to reinstall them and it still happens :/
The games load up fine but after about 20 seconds, my PC will just restart, with no error message or anything. It's weird, because no one other games have this problem except ones off Steam.
My PC is capable of playing them as I've been playing them for years before, so I'm lost.
Please help.

The games load up fine but after about 20 seconds, my PC will just restart, with no error message or anything. It's weird, because no one other games have this problem except ones off Steam.
My PC is capable of playing them as I've been playing them for years before, so I'm lost.
Please help.


, some useful information mebs? 
)