Windows 10: my pc started playing some "half-life beepeing"-like sounds and starts lagging

my pc started playing some "half-life beeping"-like sounds and starts lagging, and then my screen just turns black for a second looks similar to how explorer.exe restarting or something like that and this happens at random intervals, how can i fix this??

:)

 

Computer lagging/beeping when playing a game

Sometimes when I play a game, the computer starts lagging, and I hear a beeping sound over the speakers, like a "boop-boop-boop" kind of sound. This happens until I restart, and won't happen again for a while, until a few weeks later, and I'll have to restart again. How do I narrow down what is doing this?

 

computer not starting making beeping. 4 beep sound like piano.

computer not starting making beeping. 4 beep sound like piano. Sound is from CPU. It cause problem when no other hardware connected like monitor, keyboard, mouse, etc. It is not even connected to network lan cable. I took it to hardware store. They did some cleaning and it started working for few days and causing same problem again an again. Any help?

 

PC won't start

Went to start pc and get the beep. One beep, pause and then repeats. Reseated the RAM and it was working last night.
Ideas, helpful suggestions or cures would be greatly appreciated,
Thanks in advance for your help.