Steam games crash

Good day. The problem is the following: all steam games crash about 10-15 minutes after the start of the game, without any errors, just a crash to the desktop, sometimes after several hours, and sometimes even every 5 minutes, and after the n-th restart, you can play for quite a long time time. All other games are pirated or non-steam games don't crash at all. This nonsense started about 3 months ago, at about the same time I created a second folder for Steam on the HDD (because I have a 200 gigabyte SSD to store all the games on it). I even tried to reinstall Windows, but after a while the problem returned. All drivers are installed, the hardware does not heat up, I even checked the RAM with a meme-test, I don’t know what to do anymore, maybe someone has come across something like this ?. Windows 8.1 system