Sometimes while installing application on Windows Server you may receive an error: Error 1330. A file that is required cannot be installed because the cabinet file has an invalid digital signature Error 266 was returned by WinVerifyTrust In our case we had to install rootsupd.exe on the server before we could install the application http://download.windowsupdate.com/msdownload/update/v3/static/trustedr/en/rootsupd.exe Hope this helps