And if it is a Silverlight update causing this
, uninstalling Silverlight can be frustrating.
Try this: Backup your Registry, Search (Edit/Find) for silverlight.msi and you will find this key HKEY_CLASSES_ROOT\Installer\Products\D7314F9862C648A4DB8BE2A5B47BE100
Delete this key , and also delete all silverlight folders in programData and program files, restart. Download Silverlight Microsoft Silverlight