Normally all icons of a specific type display a standard image that identifies the kind of file they represent. You may prefer to have each bitmap graphic file icon display a small preview of the image contained in the file. This allows you to easily locate a particular graphic file by its image rather than by its name.
Show Icon Preview
To preview bitmap graphics files in their icons:
Check the Show Icon Preview checkbox.
Click Restart to restart Windows.
This kind of image previewing may cause your computer to slow down. Use previewing with Pentium 90 Mhz or better computers only.