Encountered error 1635 while updating
System Error: -292320123 This error code only occurs when using Windows Installer version 2.0 and Windows XP or later.If Windows Installer determines a product may be incompatible with the current operating system, it displays a dialog informing the user and asking whether to try to install anyway.If you’ve been trying to update your i Phone, i Pad, or i Pod touch to the newly released i OS 5, you might have encountered the error message saying that you’re device could not be restored because an “internal error occurred.” In most cases, you’ll get the “3004” error message, too. The same applies if you are getting Error 3200, or any other error for that matter. If that’s not the case, well, then hit that refresh button over and over again until it works!
It has been the same issue for Update Rollups for both Exchange 2007 and Exchange 2010.
Check your network connection and click Retry, or Cancel to end the install.