I built a few new Windows Server 2008 R2 with SP1 VMs today and ran into a problem where Windows Update is not detecting the fact that Internet Explorer 9 is already installed. Internet Explorer 9 keeps showing up as an available update when using Windows Update. When I try to install it as a test I get the error message: Code 9C48 Windows Update encountered an unknown error.
My normal build procedures include applying all the patches for the OS prior to any other work on the servers. The way I like to do the patching is to do every update other then IE9 in the begininng and once all the other updates have been completed, install IE9 and then patch it if there are updates available. I followed this procedure on every build for the last year and I have not run into any issues until today. The only difference today is the latest patches that were released yesterday April 10th, 2012. To test the theory that it may be one of the latest patches, I reinstalled Windows from scratch making sure to format the disks and then I installed IE9 right after the OS install without any other updates. Once the server was rebooted, I checked Windows Update and Internet Explorer 9 still showed up as update (Not the Cumulative Update which normally shows up after an IE9 install) and yes, I did make sure to click the 'Check for Updates' link before I looked just in case. My next test was to patch a couple of the servers I had built prior to April 10th, 2012. Those servers did not have any issues with the latest updates and they are not experiencing the same behavior as the newly built servers.
I ended up comparing the IE9 Version on the cleanly install OS (No updates were installed except IE9) and the servers I built last week which were patched. The versions are exactly the same.
My findings above lead me to believe that there is a problem with the latest IE9 install package (which includes the latest cumulative update) and the Windows Update detection component.
I guess I am looking for someone to report this up the chain to get this fixed so no one else runs into this problem. I know in some cases we may not be able to see additional IE9 updates until this is resolved.