I recently had the requirement to refresh the Windows desktop after certain changes had been made to Explorer’s registry entries. This seems simple at first: klick on any item on the desktop and then press F5. It wasn’t, though. The registry changes would be made upon logon by a software installation agent. It was expected by the customer that the end user see the the effects of the change immediately without any user intervention. That sent me hunting for a solution on the internet. I came across many forum posts that showed that many others already had exactly the same requirement. Interestingly, none of the proposed solutions actually worked. Except for one, which I found at last.
What I Wanted to Change
As you may know Microsoft stripped the ability to enable display of an Internet Explorer icon on the desktop from Vista’s GUI. However, it is very simple to add an IE icon to the desktop with a simple registry change:
Implementing this in a script was a no-brainer. What gave me a headache was this: how to convince Explorer to reread it’s registry entries and actually display the thing without prompting the user to log off and on again.
How to Do it
The solution, once found, is simple, as always. There is an API function that tells the shell that file associations have changed:
SHChangeNotify (SHCNE_ASSOCCHANGED, 0, 0, 0);
SHCNE_ASSOCCHANGED is, by the way, defined as 0x8000000.
This effectively triggers a refresh of the desktop. And voilà, the IE icon appears.
I suspect that this correct solution to the problem is so seldom mentioned on the internet because few people know how to operate a compiler. That is unfortunate and cannot be remedied by me. What I can do is provide a simple command line program that does nothing but call SHChangeNotify with the parameters quoted above.
DesktopRefresh.exe has been tested on Windows XP, Vista and Windows 7. It should work on any Windows OS from NT 4.0 upward.
DesktopRefresh, 1.0, x86 (recommended for most).DesktopRefresh, 1.0, x64