Originally Posted by jon_264

One possibility is that it could be a video file you have in that folder that you don't have the correct codec for. I had this problem a while ago and got round it by changing the view type from thumbnails to list. This stopped windows from trying to display a thumbnail for each video file.
Using a process of elimination you could move video files from this folder to another folder in the order of most recently added and work backwards till the problem stops. Then you should be able to identify the file that is causing you the problem and fix it by getting the correct codec of deleting the file.
Can you actually play all the video files in this folder or are some causing problems?