Laptop gets hungup when attempting to Defrag, Scandisk, and disable firewall

[Paul]

Hi-

I have an HP Laptop with Vista. Lately when I try to Defrag, nothing
happens. I click the window
and get the "bell" sound and have to click alt/control/delete to close
it. This happens also when I try to run a scandisk.

I've been trying to run a Windows Update, but get a failed message
with the error code 8000B100.
I read that if I disable my firewall that might allow me to do the
windows update, but I kept the same thing that happen when I
defrag.....I get the spinning circle waiting for something to happen.

I've run Lavasoft and Malawarebytes. I've tried doing this stuff in
Safemode too but I'm not really sure where to go from there.

Any help/advice would be appreciated.

Thanks