Whatever you do, (installing and updateting or unistalling) always as a
adinistrator.
Can you gº to Windows Update, select Express (Get high-priority updates),
and apply all offered updªtes http://update.microsoft.com
Once that is finished, can you verify the update installs? There are many
pre-requisite files which are needed from windows update and signature update
with windows defender will fail until you hªve these files.