The 'Office Automatic Updates' Scheduled Task would kick off during the deployment. This upset MSIExec to no end. We would get random install errors when a step was trying to install software. Many were 1618 but other strange ones like 1603 and 1638.
The fix we chose was super simple. I just put in a step to change the UpdateURL reg entry for the update path. This causes the scheduled task to exit since there are no updates found. Later on the baseline (see previous posting) changes it to what it should be. We looked at other options around modifying the scheduled task but this is the simplest solution. Now everything installs like it should.
reg add "HKLM\SOFTWARE\Microsoft\Office\15.0\ClickToRun\Configuration" /v "UpdateUrl" /d "\\my.domain.com\FakePath" /f
Note that for Office 2016 they moved this up and out of the version key.
reg add "HKLM\SOFTWARE\Microsoft\Office\ClickToRun\Configuration" /v "UpdateUrl" /d "\\my.domain.com\FakePath" /f
This key is put as close to after the Setup Windows and Configuration Manager step as you can. If your not using baselines or something else to manage this information you can change it back to its proper location as a final step in the TS. This should be a path that exists so there is no timeout concerns so we just went up a folder.