WindowsUpdate not working "Unable to install updates"

When I try to install new updates my AutoUpdater downloads every update and
askes me
if I want to install those. After I click yes it seems like it is installing
but than it gets me a message "Unable to install updates"
So I go manually to microsoft.updates site. It checks my computer for
updates and lists all the updates. I select all critical once. I notice on
the right it shows total number of updates BUT 0(zero) KB size for those
updates. Neither Express or Custom install works - same message "Unable to
install updates" after downloading.

So I have to go to each update individually, click Details and download it
and install it - this way it works.
Note: I have genuine Windows, came with PC I bought from Dell.