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 page. However the .zip file type was still showing the Adobe Reader icon, although the association settings are correct.
Forcing an "Icon Cache" Refresh
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. Programs use the SHChangeNotify API call specifying the SHCNE_ASSOCCHANGED event, in order to refresh the icon cache without requiring a reboot.
Other Methods to Clear the Icon / thumbnail caches
About the author
Ramesh Srinivasan founded Winhelponline.com back in 2005. He is passionate about Microsoft technologies and has a vast experience in the ITeS industry — delivering support for Microsoft's consumer products. He has been a Microsoft MVP [2003 to 2012] who contributes to various Windows support forums.