I had a very strange problem on my PC lately where I couldn't delete a folder (running Windows 7 Pro, SP 1). No matter what I tried to do, the file would not allow me to delete it. Instead, I kept getting a "Folder not found" error (or something to that effect). I tried to move the folder; I tried to rename it; I rebooted (both hard and soft reboots). None of the proposed solutions I found worked. There was no other program using the folder (it was empty, and even after a complete reboot, before opening any programs, it still wouldn't let me delete it).
Thankfully the Internet is full of information -- some of which is actually useful -- and I found a site that answered the problem. However, it was a bit old, and the information was buried a bit down the page. Here's the original link for reference.
So how did I solve the problem? I had, by God's Providence, literally just installed 7-zip, which is the program that the member of the forum in the above link ("kami205") used to solve the problem. The solution was simple. I opened 7-Zip (a program not developed in any way for this use), browsed to the location of the folder on my PC, renamed the folder, and then deleted it (I actually had to rename it two different times before it would delete).
That's it! It was that easy. Hopefully this helps somebody else out there who is experiencing this annoying problem.