Cannot edit registry or make changes in System Properties Tab

My computer was running slow so I ran a virus scan & had a few adware & spyware problems, which I deleted. I restarted the computer (Dimension E510). I then tried to go into the registry to verify that they were removed but found that it is locked up & my cursor does not work anywhere in the registry. The screen is colored gray, which isn't right either. I also can't do anything in System Properties. Do I really have to run Dell PC Restore in order to fix this problem???

 

Also, there is an annoying pop-up that I can't get rid of - Total-Pc-Protection - saying that my computer is infected & I need to order their stuff immediately.

 

Any advice would be greatly appreciated.