XP SP3 will not install

Hi,

PA Bear sited a web site a few days back that was designed, I think,
the type of problem I've had. Ceptin it did not work. I updated XP
to SP 3 about 3 weeks ago. Sigh, just after scanning, pruning and
doing all sorts of maintenance. Then the OS starts doing a freezing
up and constantly running memory in the background. Because I had
just primped everything I did not realize I was infected with Trojans,
etc. So, I uninstalled everything I had just installed, including
XP3. Now I cannot reinstall it again.

I made the registry changes, which were duly accepted for a missing
..dll file. Any other ideas?

Thank-you,
Molly

PS.. I'm also the person who is missing the IE Cache. Really cannot
find it. Have uninstalled and reinstalled XP 7 and still, no cache.