Windows Update control panel displays an empty page with some crooked tags like "#elementmoduleheadertext#". It is not possible to click any button or do anything in this window.
It's a VM, migrated from PVC host with a c2v procedure.
windowsupdate.log contains the following (or similar) messages :
2013-09-18 21:42:03:365 1544 de4 WUApp WARNING: Win7 navigation page code failed with error 0 2013-09-18 21:42:03:386 1544 de4 WUApp WARNING: Error displaying Opted In Service summary: 80070716 2013-09-18 21:42:03:387 1544 de4 WUApp FATAL: GetProperty "lastSuccessfulDetectionTime" failed with hr=80070716 2013-09-18 21:42:03:387 1544 de4 WUApp FATAL: GetProperty "auOptedInServiceText" failed with hr=80070716 2013-09-18 21:42:03:392 1544 de4 WUApp FATAL: GetProperty "updateSummaryImportantText" failed with hr=80073B01 2013-09-18 21:42:03:392 1544 de4 WUApp FATAL: GetProperty "updateSummaryOptionalText" failed with hr=80070716
Windows Update Agent is corrupted on the machine.
Run the Windows Update Agent Installer to repair it.
The installer for version 7.6.7600.256 (the latest available one to this point) can be found here