Please note that if you uninstall some of the updates that cause this (such as KB2794707, KB2817371, and SP2) if you have your computer configured to automatically download and install the updates, Windows will reinstall them and cause this error.
One support forum user reported that his event log was full of such events after installing hotfix KB2817371. After uninstalling the hotfix, the warnings disappeared.
Several users reported that this event started being recorded after the installation of Office 2010 Service Pack 2. From a Microsoft support forum:
"The Outlook Team is aware of this issue and is investigating it for a fix.
These bugs in SP2 and KB2817371 are both tracked individually meaning that when a fix is found it will most likely be both a pre-SP2 and post-SP2 fix (so SP2 won't be a requirement).
Initial investigation shows that there is no actual hard done to the system so there isn't any direct need to uninstall SP2. If this changes, it will be posted in the Know Issues section of the KB articles of these updates."
On a Windows 7 x64 running Office 2010 SP1, this event was being recorded about 20 times when Outlook was started. Uninstalling the KB2794707 Microsoft Outlook Security Update fixed the problem.