I'm assuming that the properties for the icons are correct (i.e. you didn't somehow tell Explorer that you actually wanted all the icons displayed as Access). If the properties are correct, and Windows is just confused about what to display, you can take a more direct approach than TweakUI by deleting the file C:\WINDOWS\ShellIconCache. This can grow pretty big, and if it gets corrupted, you'll get display anomolies like you describe. It can also screw up the icons that show on your Quick Launch bar, your Office Toolbar, macro buttons in Word/Excel/etc... I've even seen it mess up the command buttons in AutoCad. Once it's deleted, reboot and Windows will build you a new one. On systems with lots and lots of desktop icons, buttons, etc, this can be a recurring problem. If that's the case, see MSKB article Q132668 for more info on how to increase the default size of the file.