The system tightly hangs after 3-5 minutes after turning on the PC

Welcome. In General, such a problem. In the summer of 2015 moved into the top ten, when Microsoft give it away for free, and since then, until recently, had no problems. But then the wind started to happen some hell. Long included, hampered after start, and then began to disappear and the sound (headphones connected to the monitor, which in turn is connected via HDMI), and helps only restart. Often dropped graphics driver (with sound, of course). A computer 80% of the time off when activated, fast run, although in the past it has happened very rarely. The apotheosis of all steel brake after enabling the cursor moved with considerable delay, and in General, all shamelessly Vistula. Decided to reinstall from scratch (formatting the disk), hoping that it will relieve problems. The old problems disappeared but new ones have arisen. Almost every time you turn start "Preparing automatic recovery" that has failed. And, eventually, to start using the computer, we had one or two times to restart it. A little later, by some miracle, began to run fine, but then started another shit — shutdown and restart after 3-5 minutes after startup. Removed automatic restart in case of failures, in the end, after that time, it just hangs perfectly still and unresponsive. After a reboot all is fine. And if after 5 minutes of unresponsiveness was not, then all this time, the system works fine. Eventually decided to download the Windows installer from the office. website and install over your current one, preserving all files and settings. The installation was successful, all updates installed and while complaints about the work PC is not. But I don't think it solved the problem.
And coincidence or not, but after reinstalling (two weeks ago) processor with a graphics card at the same time suddenly began to warm by 3-4 degrees more. Earlier helped cleaning from dust, and now it did not save the situation. Whether because of the Windows, whether something is wrong with the kit.

Who thinks about this? What could it be? I don't know on what to sin and what to do.