If the pictures are valuable enough to be worth the effort:
FIRST: Shut down the computer IMMEDIATELY.
1. Buy a copy of Norton Utilities
2. Install Norton Utilities on some other computer
3. Remove the hard drive from your computer, and connect it to the other
computer either by
a) adding it as a second drive
b) buying an external USB/IDE enclosure, and installing it into that
4. Use Norton to find out if any of the pictures can be located and
recovered
OR
1. Obtain the services of one of the fine, but expensive, data recovery
companies (Google for "data recovery"). You send the the disk, and a few
hundred dollars, and they recover all the files that can be recovered.
Good luck!
When you are done (or you give up), start working on creating a backup
process.