if you've done much work on the pc since the space has almost certainly been overwritten, if you stopped using the machine immediately it would be possible for someone with a good knowledge of Norton disk editor or similar software to recover the data. but theres no easy way from within windows
There are various means of doing this - from a few shareware applications available on the web to data recovery companies who specialise in this business. It will depend on how valuable you consider the data to be.
Norton SystemWorks has a file undelete component.
I will have a search for some of the applications on the net and post back if I have anything of interest.
In the meantime, don't defrag, install or uninstall much or do much web browsing.