All of a sudden my Dell Pentium 4 CPU 2.4GHz 1GB RAM computer running XP SP3 is not allowing me to install updates.  I don't know where to begin looking for the problem.  I am able to install software updates but not MS Automataic Updates.  Anyone have any ideas why?  Thx.

Try unloading all startup programs before installing the updates

I did and I still have the same problems.  Thanks for trying to help.

I had a similar problem and it was because some update files need to be registered. Try the following links. If these don’t work try to find the error code for the failed update and do a Google search for the error code. The 950717 link tells you how to find the code.

http://support.microsoft.com/?kbid=943144

http://support.microsoft.com/kb/956703

http://support.microsoft.com/kb/950717

By Golly It Worked!  Thanks a lot.  The problem was that the update files needed to be re-registered.  Now I'm able to update, but I keep getting an error message each time I reboot my computer saying that I must reboot my PC in order for the updates to take effect.  I've rebotted at least 10 times and still get the error message.  Anyone know how to get rid of it??

If you have automatic updates turned on I would turn off automatic updates temporarily.

Go to the following link and install the windows update agent. If you are running 32 bit windows you need to install the windowsupdateagent30-x86.exe file.
http://support.microsoft.com/kb/949104  

If you are updating by going to the Windows update web page http://update.microsoft.com/ then you may already have this version installed automatically. If this does not solve the problem, go to the Windows update web page and on the lower right corner click the button that offers the updater for both Windows and Office updates. Install this automatic updater. If the offer is not visible then you already have this updater installed.

If the problem is not solved, what error code are you getting?

After turning automatic updates off and then back on again, it seemed to fix the message I was getting saying that I needed to reboot my computer.  Thanks ABQMAN!