updates stopped (around december?)
Had the same issue here (gaming, hers and my mother, the three die hards I can not migrate) and it might be related to the silverlight update from december.
Disable automatic updates and stop the wuaserv service (the one running under svchost control and staying up at an entire core), then rescan for updates manually. Should show up with three to four important patches, ~300Mb.
Afterwards reboot and reenable automatic updates.