XP locks up at splash screen

Apologies if this has been discussed before, but I've only just joined
this group. I have a problem on two different PCs running XP home with
the latest patches and updates, but with quite different specifications
and different software in daily use, by and large. On boot-up, XP runs
as far as the splash screen. The progress indicator runs for a while and
then XP locks up. The only thing that will clear it is turning off the
power and re-starting. The machines then show the page offering to start
from safe mode etc. - if I select start in normal mode, the machine
takes the last good configuration and starts just fine. I've done this
countless times, and
it always follows the same sequence.

I read quite a few discussions on the net about this, so I know it's a
common problem, but without a common solution. The first suggestions
were that it was a driver problem, so I disabled the splash screen to
see if it locked at the same driver each time, but this was not the
case, they all loaded just fine and then the machine stopped - the
message on screen just showed the Windows version - not an error
message. I updated all the drivers I could find anyway - to no avail.
The two machines had different graphics cards, hard drives etc. so there
were not many drivers in common anyway.

Since it loaded OK from the last configuration on the *second* time of
asking it seemed reasonable therefore to assume that something was
happening on shut-down which was blocking the first load, but cleared by
the reboot. I found a conversation which blamed the problem on some
program/s keeping a handle on the Windows Users section of the registry
on shut-down. I'm not very technical, but this sounded good. I installed
a prorgram from Microsoft which purported to prevent the problem by
forcing all programs to release their "grip" on the registry before
close-down - UPHclean-setup.msi . This seemed to work for a while, but
the behaviour returned. Logic would suggest that the problem was related
to the previous shut-down. My guess (and it is only a guess) was that a
Windows update altered things. Indeed, my guess was that a Service Pack
or update started the problem in the first place, as it started just
after one, but then as there are so many updates anyway, it's almost
bound to start just after one.

Anyone any ideas as to where to go from here? The longer it goes on the
more annoying it gets.

Regards,

Bob

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