Yannick, I appreciate your reply to this. As I said, the .gg file is not always failing to install. The install fails only on 3 machines. Other machines are all installing just fine.

The weird thing is that the 3 machines that have problem installing my gadget have earlier installed the gadget with out a problem. It complains "Failed to install gadget" when re-installing the gadget. I even changed the GUID in the manifest and re-created the .gg package but that did not help either. Once it says "Failed to install Gadget", the problem persists no matter what I change. I don't know where the hook is.

And I just noticed today that on these 3 machines, it's not just with my gadget. The .gg file fails to re-install even the gadgets featured on the Google plugins site. May be some combination of software (other than Google Desktop) is causing such weird behavior on those machines and I am not sure if such install errors have ever been reported to Google before this.