Is This a Virus?

I have for a long time now used free versions of Super Antispyware and AVG 2015 as installed on my old home built Windows XP SP3 Home desktop P C. They are kept up to date with latest definitions and scanned frequently but recently cannot update or use these two programs. I get what I presume is a virus for when I try to open the programs I get notified…..’Windows cannot open program because it has been prevented by a Software Restriction Policy’. I also have Malwarebytes installed with up to date definitions. This appears to be working normally, no problems found on scanning. Just discovered cannot use System Restore either as ‘has been turned off by group policy’ notice. Part of the same problem I assume.

If it is a virus is it dangerous and is it possible to easily rectify this problem or should I just bite the bullet, format and start over again? I have read the information on this forum re this problem, but find it very complicated for me to follow the attempted cures, I am not an expert with PC’s unfortunately. Perhaps someone can tell me how to run and attach the logs mentioned in the ‘cures’ info.

Thanks to anyone who may have any other good ideas?