Why does my computer randomly crash to a Black Screen?

My computer screen blinking black and running slow after crash?

• i was playing dungeons and dragons online it started running slow so i tried to close it and it lagged more so i opened task manger it froze so i shut it down by holding the button when i logged back in my screen was blinking black repeatedly and ran horribly slow as if the crash had become part of the programming, ive reinstalled my graphics card drivers, i made more virtual memory, ive run virus and malware scans, ive done disc checks galore and cleared my registries i still havent got it to work normally

• Answer:

  There can be two issues: 1. Virus (Use AVAST free) 2.. Corrupt registry ( Use Reginout ) I am sure it will help you.