For the past couple of months I have been experiencing the following
problem which is driving me crazy:

After I log onto windows (XP Home Edition) the desktop appears
(finally) but after about 15 seconds I receive 2 messages on the screen
and I cannot go any further, I cannot select any programs, i cannot go
into Task Manager, I cannot do anything except power off the machine
with the on-off button.

Svchost.exe - Application Error
The instruction at "Ox745f2780" referenced memory at "Ox00000000". The
memory could not be "read".
(I click "ok" to terminate the message)

At the same time I receive another error:
Generic Host Process for WIN32 Service encountered a problem
(I then have the "send/don't send option)

The cursor can move around the screen but nothing on the desktop
activates when I click on it. I cannot also access anything on the
system tray at the bottom of the screen.

I am the main user on this laptop (administrator), when my wife logs on
under her name she does not receive this message.

After re-booting approximately 5 or 6 times, sometimes more, i can
finally log on successfully.

One other thing that has also been happening for about the same time is
that when I log off I continually receive the option to carry out 2
Microsoft updates, I have legitimately updated these about a dozen
times but I still get this message. It seems that something is not
being cleared out of memory properly when I log off.

Any pointers as to what might be wrong and what I could try to fix it?

Any help gratefully received!