XP Home misbehaving after SP3 update

Similar to another post I have issues with my Fujitsu Siemens Scaleo M after
upgrading (sic!) to XP Home SP3 (thoughtfuly provided by Windows Update).

The account I use (the one I used for the update) seems to be fine after I
deleted a bunch of stuff from BT Internet (their browser IE files etc), just
leaving the Core Elements and Norton Security Elements (firewall, virus
scan). The BT elements were preventing any internet access, although the
computer worked fine locally.

However, now, when my wife tries to login to her account she just gets the
wallpaper with no icons etc on it (no Start button even) and no systray so
she can't do anything. If I switch back to my account (from which I am
sending this) using the windows task manager all is fine. Her account is set
for Computer Administrator access (same as mine).

Trying to create a new account gives a blank account with the wallpaper only.

I don't want to do anything to lose my (working) account but I really need
to get my wife's account back so she doesn't kill me out of sheer frustration!

--
Rob Harrison