Not sure if you've done this before but try this. Buy one of these adapters. If you know how to remove your hard drive you can connect your hard drive to this and connect to another computer.
http://www.tigerdirect.com/applications/category/category_slc.asp?CatId=3770&SRCCODE=WEBGOONET&cm_mmc_o=mH4CjC7BBTkwCjCECjCE
If another computer is able to read your drive. See if you can see Documents and Settings, look for your user name in this folder since this is where most of your data resides. Taking your hard drive to a Data recovery specialist will be costly.