Laptop unable to open any programs...

Hi, today I was suddenly infected with "Vista Security Tool" which would not allow me to access my internet, so using another laptop in the house I discovered this was a fake security tool and a malware program. I ran one of my security programs "SUPERantispyware" and it discovered quite a few infected files, after cleaning my computer with this and letting my computer reboot I thought "Brilliant, got rid of it" but now I'm left with this problem.

I can log in and I'am presented with my wallpaper and my icons on the left hand side of the screen, however when I go to access them I'am given the "Choose the program you want to use to open this file:" box, it does it for all my icons! If I try to use anything in "Start" it either does the same as previously mentioned or I get an error box stating "application not found". I tried seeing if running my computer in safe mode would let me get around this and it wouldn't. I can still see all the files when I go through "my computer" but it doesnt let me do anything with them. Any help would be greatly appreciated if anyone could tell me how to solve this problem? Or what to do to fix it...