I had Microsoft Silverlight on my computer when purchased, Didn't think I needed it, Uninstalled it. Yet Every friking day for months it does an unsuccessful Update Install, Been to Silverlight site, says its installed, do an update, it tells me it was unsuccessful.
I usually ignore it, It bites, Microsoft, in My opinion is a Big Broken Machine.
Do I need It, If I delete it, will it do an Unsuccessful for the rest of my computers life?