Operating system
Windows Vista/Windows 7
          After booting in to windows the all desktop icons appears only after 4-5 minutes.
   Possible causes
  1. More Startup programs.
  2. Any startup antivirus scan.
  3. User profile corruption
  4. ShellIconCache file may be corrupted
In this case shellIconCache file got corrupted. Its a hidden file located at windows directory which contains a copy of the all default desktop icons. To resolve this issue, recreate the ShellIconCache file by deleting it.
Open the folder options by typing the control folders on RUN prompt. Select View  and select Show hidden files and folders and click OK.
 Locate the patch %USERPROFILE%\AppData\Local\Iconcache.db. Delete the file Iconcache.db.
 Restart  the computer.