Someone please help me out.

I downloaded the older version for Windows from the link above. I tried to run it, and when I did my PC crashed. Upon startup, I get a prompt telling me there's a Windows file missing (I don't remember what it was called, I'm on a work PC) and it says I need to re-install Windows.

Uh.. crap. I don't know what to do. Do I really need to re-install Windows? Is this all a coincidence, or did the download f*ck me over? I'm not as much of a geek as I'd like to be.

Any help is appreciated.