Microsoft Fixes Issue in Office 2010 SP1 Update
Microsoft has fixed Office 2010 Service Pack 1 (SP1) installation failures reported by some users.
The failures are described on a Microsoft support page (ID 2553092); the problems can occur when using the Microsoft Update service to install SP1. Microsoft said the service pack was available in late June, providing users with a roll-up of previously released updates, plus a few new features and fixes.
SP1 was released initially just for manual installs, but Microsoft promised automatic distribution would occur after 90 days.
Users tripped up by the SP1 install using Microsoft Update will see two error messages to help them identify the issue. The error messages are labeled "1935" or "78F." These messages typically pop up in cases "when Office 2010 was originally installed by using a temporary storage device."
The SP1 install problem is also associated with a reference within the Windows Installer program, which sometimes points to "a drive that no longer exists, or to a removable media device that contains no readable media," according to the support article. In other words, it can point to a CD or DVD drive that contains no disk. As a simple workaround, Microsoft suggests that "before you install Office 2010 SP1, put a readable DVD or CD in your optical drive or connect a USB drive."
However, those users wanting to get the fix for the problem can download the 32-bit version here. Users with the 64-bit version can find that fix here. More information can be found in a Microsoft TechNet library article.