When you install Microsoft Office 2010 Service Pack 1 (SP1) by using Microsoft Update, you may receive the following error message:
Code 78F Windows Update encountered an unknown error.
If you download and install the SP1 package from Microsoft Download Center, you may receive the following error message:
The installation of this packaged failed.
The Officesuitewwsp1-x-none_msplog.log file that is generated during the installation contains an error message that resembles the following:
Error 1935. An error occurred during the installation of assembly component <component GUID> . HRESULT: 0x80131047.
This issue may occur if the Windows Installer encounters a reference to a drive that no longer exists, or to a removable media device that contains no readable media. For example, this issue may occur when the Windows Installer encounters a reference to an empty DVD or CD drive.
Before you install Office 2010 SP1, put a readable DVD or CD in your optical drive or connect a USB drive.
To resolve this issue, download and install the following update before you install Office 2010 SP1.