Firmware updater 2.1a problem

For some reason I can't update my Sony 500A-DRU Firmware
(2.0g) to new 2.1a or 2.0h. I got a reply from another
site that the updater needs to be able to register itself.

All I know is that whenever I get to the point when it
notifies me that my computer needs to restart before
drive can be updated, I would click yes and my PC
restarts. But the update doesn't do anything upon
startup. I would click the updater again and it just
takes me back through the same procedure over and over
without updating, I would always end up with the updater
telling me that my PC needs to restart before drive can
be updated

I've uninstalled IAA (Intel Application Accelerator) and
Norton Internet Security as someone noted that these
programs prevent programs from registering. Still no
update

Can anyone help me