Slow opening of folders or videos.

Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Home Premium, Service Pack 1, 64 bit
Processor: Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz, Intel64 Family 6 Model 42 Stepping 7
Processor Count: 4
RAM: 6048 Mb
Graphics Card: Intel(R) HD Graphics, -1988 Mb
Hard Drives: C: Total - 939431 MB, Free - 346953 MB; G: Total - 476937 MB, Free - 151689 MB; L: Total - 953835 MB, Free - 95044 MB;
Motherboard: Gateway, IPISB-VR
Antivirus: Panda Free Antivirus, Updated and Enabled

I have a problem with folders and video's opening way too slow.
when I try to open some folders, they have a green line across the top that slowly go from left to right. It takes several minutes on some folders to finally show all of the items in the folders. It will show the folder names under where the folder should be, but not the folder icon. They will finally appear after a long time.

Also some videos in the video folder will take a long time for windows media player to start playing the video.
These are home videos and they use to start immediately.

I have done scans with Avast antivirus and replaced it with Panda with the same results.

Thanks for any help that you can give.