You need to rebuild your icon cache. To do so, follow instructions:
1. Open the Windows Explorer file manager.
2. Within Windows Explorer, use the toolbar menu and click on Tools/Folder Options/View and select "Show hidden files and folders" and then on OK.
3. Using Windows Explorer, go to C:\Users\(User Name)\AppData\Local and right click on IconCache.db and select delete.
4. Click on Yes to confirm the deletion.
5. Close the window.
6. Empty the Recycle Bin.
7. Restart the computer.
(Don't worry about deleting the file, it regenerates itself on restart of computer) Icon Cache - Rebuild