How to retrieve deleted hidden file?

Hey Guys,
I got a big problem with my Vista machine. I am trying to do a clean up on my computer. Unfortunately, I have used a shift + delete function and I have deleted one of the hidden files.
As of the moment, my computer is running smoothly, but I am worried that in the long run, I might get issue because of it. How do I deal with this? Can I get it back?
Thanks.
