I would suspect that they are going to be hard to recover
I usually recommend using PC Inspector File Recovery
But since you used a Shredding program to remove them
Chances are they're gone for good
Files are gone when normally deleted, a program such as PC Inspectore can recover them because the area on the disk has not been overwritten yet
but with a shredding program
It would of probably overwrote the area that the photos were at a few times to ensure you can't restore them
There are high priced services that may be able to recover them
But I mean high priced
You actually have to bring your harddrive into them
Keep in mind, the more you use the computer, the chances of recovery go down even further
You will overwrite the area again where the photos were stored
Personally, I would consider it a learning experience and ensure to Always backup important files and folders
You can try this program, I haven't used it before
See if it will help, but I doubt it
If possible, run it from a USB thumbdrive or similiar
http://www.recovermyfiles.com/?file=RecoverMyFiles-Setup.exeIt's free to try and scan your computer
If the photos are recoverable, you will have to purchase it however
Here's another free product, Restoration
Again, I don't think it will restore the photos though
http://www.aumha.org/freeware/freeware.php#restore