Workstation Icons

I am running NT 4 with SPA 6a. My desktop icons are displaying incorrectly. The majority of them display the Microsoft default icon for files it doesn't know what program to associate them with. But all the icons do operate correctly. I've tried uninstalling the Service pack and re-installing it several times with limited success. Some of the icons will come back and some won't. I've also went as far as to delete the "ShellIconCache" file from the %systemroot% directory. One other possible fix was to change the icon size in the display properties. This action also had limited success. Someone out there has to know how to resolve this issue! Please let me know!!!!!