Folder In My Documents Cannot Open - Flashes When Clicked Then Nothing

I have a folder in My Documents that doesn't open up (other folders in my computer works fine). I double click on it and it makes that clicking sound and flashes for a sec but nothing opens up. I can only look at what's in the folder by using Word 2007 then open and select all files. I scanned it with AVG and there's no virus. Most of the stuff in there are not downloaded, it's mainly documents which I typed on this computer, and the few things that have been downloaded I have opened before and there never seemed to be a problem until recently. I made a copy of the folder to an external hard drive and funnily that opens up. I tried to delete the original folder in my documents but it says folder in use and won't let me delete it.

System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Ultimate, Service Pack 1, 32 bit
Processor: AMD Turion(tm) X2 Dual-Core Mobile RM-72, x64 Family 17 Model 3 Stepping 1
Processor Count: 2
RAM: 3581 Mb
Graphics Card: ATI Radeon 3100 Graphics, 256 Mb
Hard Drives: C: Total - 293563 MB, Free - 84065 MB; H: Total - 953867 MB, Free - 415416 MB;
Motherboard: TOSHIBA, Portable PC
Antivirus: AVG Anti-Virus Free Edition 2012, Updated and Enabled