A recent post caused the thread at http://answers.microsoft.com/en-us/office/forum/office_2010se-word/microsoft-office-2010-updates/89df547d-c078-41ad-9922-8c1b00e265d5#LastReply to reply, and the last few posts there make it seem likely that the popup
is genuine. For example, WildByDesign writes:
From my understanding, the popup being referred to here is likely from the Click-to-Run Application Manager. I'm not sure why some of the MS support people here don't seem to be familiar with it. It's found within the Control Panel.
That is what takes care of all of the updates for Office Starter 2010 since it is based upon Click-to-Run virtualization technology. Updates are installed to Starter through the Click-to-Run Application Manager, not through Windows Update, and since these
updates are streamed that is the reason why an Internet connection is needed to stay on at least for the duration of the updates. Click-to-Run Application Manager automatically takes care of all of those updates for Starter and so that is safe to proceed
with those updates and no worries, it will not install IE10/11 since it is not associated with Windows Update. You can always run Click-to-Run Application Manager from the Control Panel manually as well to look for updates. Although updates for Starter are
becoming fewer and farther in between.