Windows Update Nightmare

So, I have Windows 2003 Server Standard Edition, running on an AMD
1.0Ghz CPU with 512Mb of ram and three HD's, a 20, 30, and 10 gig.

The OS is on the 20 gig, which is the primary boot drive.

ASUS A7V KT133 Motherboard

ATI Radeon 7500 all in wonder graphics card

....

So, I've been trying for months now to get the Windows Update to do an
update on the system, what I get when I try it is any combination of
the following...

Explorer.exe crashes on logon, Taskman can be loaded, but if you
manually run explorer.exe it still crashes.

Error as follows:
Application popup: Explorer.EXE - Application Error : The instruction
at "0x77ddb69b" referenced memory at "0x0101364a". The memory could not
be "written".

When I'm not getting that error, which I have no idea how to resolve
from the command line, and it happens even in safe mode, the system
gets into a reboot loop where it just reboots over and over again - it
does this after the "Windows Server 2003" startup logo appears but
before the GUI actually starts or gets to a login prompt. Does it even
in safe mdoe.

Those are the two primary errors, I've tried the Microsoft Baseline
Security Analyzer 2.0 and it can't scan for proper updates for some
reason giving me an error that I can't find on the web anywhere.

In addition, I keep getting a weird DCOM error on the eventlog that may
or may not be related:
The server {BA126AD1-2166-11D1-B1D0-00805FC1270E} did not register with
DCOM within the required timeout.

or

The server {8BC3F05E-D86B-11D0-A075-00C04FB68820} did not register with
DCOM within the required timeout.

or

DCOM got error "The service cannot be started, either because it is
disabled or because it has no enabled devices associated with it. "
attempting to start the service SENS with arguments "" in order to run
the server:
{D3938AB0-5B9D-11D1-8DD2-00AA004ABD5E}

Very weird.

In addition to all that, reading the event log says I have errors
installing updates:
Installation Failure: Windows failed to install the following update
with error 0x80070080: Update for Windows Server 2003 (KB910437).
Installation Failure: Windows failed to install the following update
with error 0x80070641: Update for Office 2003 (KB887980).
Installation Failure: Windows failed to install the following update
with error 0x80070080: Security Update for Windows Server 2003
(KB899591).
Installation Failure: Windows failed to install the following update
with error 0x80070008: Security Update for Windows Server 2003
(KB896428).

(these are not all the errors, just a few of them)

So, can someone, please, help?