“Error Code 9C48: Windows Update encountered an unknown error.”
This error occured when trying to install the following update “Windows Internet Explorer 9 for Windows Server 2008 R2 for x64-based Systems.
- Download IE 9 from Microsoft’s Download Center. Here’s a link to the version for Windows 7 and Windows Server 2008 R2 64-bit: http://www.microsoft.com/download/en/details.aspx?id=23332
- Uninstall IE9, if you already have it installed, and restart the system.
- Disconnect from the internet. This is important because the installer attempts to download the latest, bad binaries from Windows Update.
- Let the install finish and then restart system.
- Reconnect to the internet and check Windows Update. You should be able to see the Cumulative Update for IE9, instead of IE9 itself.