Sorry, forgot to mention... John is right about your restore points being gone, even when you get System Restore to work again.

It will take a lot of virus scans to eventually remove the infections, but it can be done.

Micro$haft's 'Windows Defender' is actually pretty good at finding and removing these things, but you need something like AVG version 8 (free edition) as well - installed in Safe Mode so as to avoid being hijacked.