So many things going wrong!!

I don't want to have to reformat my hard drive, but something crazy is going on with my computer. I have not tried the "Read & Run Me First" yet because I am not sure if this has anything to do with Malware.

Maybe someone can point me in the right direction. Yesterday, Comodo went crazy while one of my kids was on the computer. He said a window popped up that by description sounded like Malware that advertises false anti-virus software. He said he clicked on something to do with firewall. This may or may not have done something with necessary files needed to run our computer. The computer has not been right since.

I tried to system restore, but the Software Distribution Service 3.0 had installed that morning and it won't let me go to a restore point previous to that.

At this point, I forgot to add, the display settings went down to like 4 bits and 800x600 pixels and would not allow me to increase it.

Also, many files are now saying access denied. When I try to open many programs, including Firfox, it gives me a message saying that Windows cannot access the specified device, path, or file. Other things I try to run may also say "Failed to Find a Suitable Display Device". When I repaired Windows, I did get my display settings went to default but it still does not recognize my graphics card.

I have tried to repair Windows and I also reinstalled the drivers for my graphics card. Regarding the graphics card, I was also getting error messages about the computer either not being able to access or not find files related to it. I have read complaints about something going on with one of NVidia's recent udates and believe that part has something to do with that.

Where do I start?

Thanks!
Melanie