Recently I received a query wherein the user had incorrectly associated .zip file type with Adobe Reader. Later they got the association problem straightened out by running the .zip association fix from the File association fixes for Windows Vista page. The problem is that the .zip file type is still showing the Adobe Reader icon, although the association settings are correct.
FORCING A REFRESH OF THE ICON CACHE
Usually, the icon should be refreshed after a restart. If that does not happen, you can force a shell icon refresh by performing a task that triggers the calling of SHChangeNotify API. For example, you can use the Default Programs applet and set Internet Explorer as your default browser, in order to refresh the shell icons. Follow these steps:
1. Click Start, Default Programs
2. Click Set your default programs
3. Select your web browser, email client or any other item in the list.
4. Click the Set this program as default button.
5. Click OK.
Check if the icon for .zip file type is fixed.
Whenever the file association settings are changed or new association is created via the registry or script, the system might not be aware of the change unless the SHChangeNotify API is called specifying the SHCNE_ASSOCCHANGED event, or until the system is restarted.