Programs won't open on computer? Help!?

I thought I had found a virus on my computer that had been giving me all these advertisements for windows xp virus protection, and it started not letting me open my Internet so I went on my expired virus software (it still had some useable features) and found the path to something that seemed suspicious and it showed the path where I thought it was and deleted it with realizing what I had done. It was in application data and it was called "wbo.exe". After doing so everytime I try to open a non system related program it just pops up with a "open with..." box, I have tried using other programs to open Internet explorer and such but I keep getting the same thing. My computer is now left useless to do anything but browse files on the dads drive. Please help, I will die without my computer.