My computer keeps displaying black screen. Help!!

It’s win8.1. I’ve been getting a few ‘blue screen’ and now everything’s fine till I hit enter button in the log in screen. I see the mouse arrow but the whole screen is black. Is there any way? Am i supposed to install a new copy?

Am i supposed to install a new copy?
New copy of what?

This is the viruses and worms forum section for posting malware and false positive problems

If you have a malware problem, follow instructions in the sticky post at top in this forum section > Logs to assist …

If this is your issue, maybe this help > https://forum.avast.com/index.php?topic=189503.0