We got rid of a virus, and now nothing is working, how to fix?

We spent all morning getting rid of this Vista Security 2012 virus with McAfee Security. The virus wouldn't let us access anything, such as internet and Microsoft word, things like that. So, my mom put in McAfee security and it seems like we got rid of it. But whenever we click on the internet, it says that 'the application cannot be found'. I tried to access a game I had installed and it came up with this window that said to open the file with which program, and it showed all these programs, but I tried clicking on one and the window with the programs opened up again. I'm not a computer whiz (no one in my family is) and we're stumped. Is there a way to fix this? I'd appreciate help, not bull crap answers, like 'your computer is toast, sorry' or 'sucks for you'. Thank you in advance!