Black screen with cursor

I was using my computer when my AVG Anti-Virus popped up with a warning about a virus. I asked the AVG program to take care of the virus but it could not. This is where the problem may lie. I though that maybe another Anti-Virus program may be able to resolve the problem. So I downloaded AVAST Anti-Virus from a site I have used before and started a scan. The AVAST Anti-Virus program asked me to reboot after I ran the scan and that is when I started having trouble with a black screen. When my computer boots up it goes directly to the safe mode without me having to press the F8 button. It doesn't matter what part of safe mode I choose to use, I still end up with a black screen and cursor. So therefore, I do not know what to do next. I have tried task-manager and that will not come up either. Is there another way to get into my computer besides the task manager and safe modes which do not work and bypass that stupid black screen and cursor. I can hear the cpu running. I would use the malware you suggest before posting, but I can't get past that black screen with cursor. If you know how to do that I will be more than happy to run the malware scan. I am coming to you guys for help before I have to go dish out a bunch of money to fix it. Thanks

 

Can you please read and respond to the fourth sticky at the head of this forum? We can't help without information.