Virus affecting exe files

I have a virus that is affecting my executable files. I was online and SAS notified me of an incoming virus while on facebook and started the scan. Well when it was said and done whatever application I tried to opened i got the open with.......window. I am unable to start in safe mode, I am not able to use system restore, I can't change user accounts. Oddly enough, if I click on a word file it will open, and I can access the internet......I guess the dirty bugger wants to maintain access so that it can continually update, heck I don't know what to do it is very frustrating trying to figure it out. Help me Major Geeks I so desperately need it. Thanks!

Elaine