Hi Dean,
The ShellIconCache contains a copy of the icons for desktop objects. And according
to the following Microsoft Knowledge Base Article the ShellIconCache file is
permanently excluded from being defragmented. For more information see the following
Microsoft Knowledge Base Article:
KB227350 - Files Excluded by the Disk Defragmenter Tool
http://support.microsoft.com/?scid=227350
The file can be deleted, and will be recreated. I am not sure you will gain anything
by doing this and then running the defragmenter. See the following Microsoft
Knowledge Base Article for detailed instructions on how to delete the file.
KB216165 - Changes to Desktop Objects Are Not Displayed Properly
http://support.microsoft.com/?scid=216165
For more information on effectively using the Disk Defragmenter tool in Windows 2000,
troubleshooting, and links to additional information see the following Microsoft
Knowledge Base Article:
KB318759 - HOW TO: Use the Disk Defragmenter Tool in Windows 2000
http://support.microsoft.com/?scid=318759