My computer is on the edge here. I think someone has hacked my computer some how. I have a load of problems. I suspect a virus has caused this, because earlier this week I downloaded something and Avast Anti-Virus Professional found 7 or 8 trojan horses and malware.
Here is my problems:
1. Task Manager disabled:
When I press CTRL ALT DELETE or go down to the task bar and right click and select task manager, it says it was disabled by the administrator, and I am the administrator. The only other account on this computer is the guest account. This is so screwed!!!!

2. "Black Screen Clicks" as I call th***em:
Sometimes when I click stuff, my screen goes black for a second, and then it returns and my icons on my desktop reload, and the thing I clicked doesn't come up.
3. Tab Pop-ups:
When I am surfing the web, Some popup ads come up, but they are not normal pop-ups, they open a new tab instead. As you can see up in the error above, where it shows the "***", one of these Tab Pop-ups happened while I was typing that very word. Is some kind of adware or something in my PC?
4. I am unable to do virus scans:
I can't do virus scans, When I delete the infections at the end of a scan, it only deletes 3 or 4 then some weird code error message comes up. Or if it doesn't do that, I can delete them, but it does no good to my problems. HELP ME PLEASE!