Windows Update says this is an important update, but it will not install.  It always fails and gives me error 80070643.  I tried downloading the file manually and installing, and I get a fail on that too.  Any ideas?

This is a Windows 7 machine.  Office Products listed include:  Microsoft Office 2010, Microsoft Office Click-to-Run 2010, and Microsoft Office Starter 2010-English.

Hi,

After doing some research, I found KB903772 and this thread. Though KB903772 is for Office 2003, I would suggest we give it a try. Steps are:

Method 1: Determine the status of the Office Source Engine service

To determine the status of the Office Source Engine service, follow these steps:

1. Click Start, click Run, type services.msc, and then click OK.
2. In the list of services, double-click Office Source Engine.
3. View the Startup type list.
4. If the startup type is set to Disabled, change the startup type to Manual. To do this, click Manual in the Startup type list, and then click OK.
5. Try to install the Office update again.

Let me know if this solve your problem, if not, we can keep checking, thank you.