Windows XP Slow desktop and start menu

Archived from groups: microsoft.public.windowsxp.perform_maintain (More info?)

Hello,

I am working on my fiance's computer, a Dell Dimension 8100 with a Pentium 4
1384Mhz processor and 128MB of RAM with XP Pro SP2 and IE6. I have AVAST,
Spybot, and Adaware running. I have used Tweaknow regcleaner, The Ultimate
Troubleshooter website, cleaned the pre-fetch, cleared the IE temp files,
cookies, etc. I have disabled quicktime and musicmatch and something from
MSOffice from loading on startup. I have deleted all the programs that she
doesn't use, used the diskclean and defrag feature and read through most of
the posts regarding slow XP performance. The post by Shenan Stanley regarding
slow startup/slowdown was especially nicely done...but I had already been
through those steps. Her computer is completely updated and she is using the
most current drivers. THE PROBLEM IS...her bootup is slow. It goes through
the XP window screen fairly slowly to the part where programs start loading
(you can see the desktop at this point) at which point it slows to a crawl.
It will take 2-3 minutes for the few startup programs to load, icons to
appear and startup routines to finish. Even after that time, when you open IE
(either by quicklink, shortcut, or menu) it takes almost 1 minute for the
page to open to msn.com. We are running on a cable modem. If you click on the
start menu, you may wait for 30 seconds for the menu to come up, and again at
each junction in the menu. Some programs are even slower. When you shutdown,
XP can take 2 minutes to shutdown as well. The computer is basically unusable
at this speed. SO, what do I do to speed her up?