Files aren't actually deleted until they are overwritten (though they're no longer available through conventional methods). If you decide to try these recovery programs, you should stop using your hard drive immediately so you don't overwrite the data you are trying to recover. Slave it to another PC and run the recovery from that PC. Even now you may have permanently lost some of them if you're using that same PC. If you can't do that (slave to another PC), you run the risk of overwriting the data with every action you do on the PC (but you still may be able to recover some or most or even all of the files - it's a matter of luck). I realize we're talking only about one file here, but the process is essentially the same with one file or many files or all the files (I just didn't revise the paragraph to read as applicable to only one file).
http://www.snapfiles.com/Freeware/system/fwdatarecovery.html(try Recuva ONLY - do not purchase any products that aren’t free – here or in any of the other links – I’m just suggesting the FREE options and have had problems with some of the commercial ones) - this is the same as was previously suggested and I also think is the best one.
Only you can decide if the data is important enough to take the PC to a data recovery expert to recover the files (they will have better programs and equipment to do so than any of us do and than I provided above). Do NOT go to Geek Squad or any of those big store centers - they mostly don't know what they're doing - take it to a data recovery expert. It will cost quite a bit (I mean, a LOT) and they usually offer no guarantees – you typically pay the same price if they recover everything or if they recover nothing. The decision is yours.
I hope this helps.
Good luck!
P.S. If you have Vista Basic or Vista Premium, Shadow Copies is not available; however, there's an alternative that's free and mirrors the functionality of Shadow Copies available only in the more expensive versions called Shadow Explorer. http://www.howtogeek.com/howto/windows-vista/recover-files-with-shadow-copies-on-any-version-of-windows-vista/. Though it won't help you this time, it could very well save you in case this happens again.
Incorrectly posted it wasn't free. I've removed that as after checking further (and reading the whole page instead of skipping to one section only) I confirmed a free version is available as compuwhiz93 indicated.
You're right - I was looking at the mobile recovery version at the bottom instead of the free version listed at the top. My apologies. I've amended my prior post accordingly.