By default, Windows Explorer in Windows Vista shows thumbnails of files and also superimposes the file icon on the bottom-right of the thumbnail for documents of some type. If you do not like this feature then you can easily disable it. Here is how :
- Open any folder.
- In the folder, select Organize → Folder and Search Options as shown,
- In the Folder Options window, select the View tab.
- Uncheck the checkbox labeled Display file icon on thumbnails as shown,
- Click OK to save the settings and close the File Options window.