(cross-post added to Office Update)
Always disclose your OS and version when you want help,
even if it is about a specific product.
E:\>set /a c = 0xA9B
E:\>net helpmsg %c%
The system cannot find message text for message number 0xa9b in the message file for NETMSG.
Does the installation of Office products make that message number defined?
Are you sure you have the right code? FWIW nothing useful comes up with
this search by either Live Search or Google web search:
(0x0A9B OR 2715) code office site:microsoft.com
Otherwise what you should do is search your harddrive for files which the
update wrote to (during the time the update was running) which contain either
representation of the code and look for the context that you find it in.
BTW as another poster has already mentioned you are more likely to get
informed help about updates to Office products in an Office newsgroup.
Cross-posting for convenience.