Lost File RecoveryFollow

Recently a folder on my computer's contents randomly vanished for no reason. I was doing nothing to the files and no one had touched my PC. It was about 10-15 gb of images and text files. I'm curious if anyone could point me to the easiest way to attempt recovering the files. I am certain they are no longer there or in the recycling bin. Tried a search etc. Tried one recovery program but it was extremely confusing and only resulted in me finding some images that haven't been on my pc for months. I'm wondering if there is a program that I can use to recover the contents of a specific directory or recover and find a specific file type?

Generally, when data is deleted the space is considered "free" by the system. The actual data is still there but the markers for the data have been removed. This then allows the drive to overwrite it, basically.

In addition to the above posters software suggestion, you can also try the following:

System Restore (which might or might not work. Usually doesn't but it's an option)
Check the recycle bin (although files of that size are generally deleted and not stuck there)
R-Undelete - pretty good software for recovering data. Had a client lost a big chunk of her stuff and this helped me restore about 60% of it.

As a rule however, unless you have a backup someplace, the odds of being able to recover deleted directories, especially when you have used the PC after the fact, are slim to none I am afraid without costly software to do so.