Windows Directory Tree Never Finishes Loading?

I am running Windows 7 64-bit and since yesterday whenever I open “My Computer”/“Windows Explorer” (-Windows+E) the initial “showing drives” screen is frozen, so I have to use the address bar to navigate to the path I need to go.

As you can see in the picture to the left even after you have gotten to and are viewing the folder you want, the directory tree in the sidebar continues to “check” for “who knows what”!

Anyone got a solution to this?