System Settings Not Saving

Any advice here?
I have been trying to save mouse settings, system icon settings (in taskbar
notification area. Most of the time they are greyed out anyway and can't be
selected, other times [on reboot] they are there and selected, but most of
the time they are greyed out and unselected and not on the taskbar) for
volume, power, networks, clock, etc.
I have tried disabling the UAC (user account control), rebooting, setting
the desired settings, applying, rebooting, re-enabling UAC, rebooting... and
the settings are back to default! This is very frustrating.

SYSTEM INFO:
Vista Ultimate
HP DV8000t
Intel T2500 @ 2.00GHz
2.00GB RAM
50GB Free HD Space
NVIDIA GeForce Go 7400 WDDM