~10 minutes to boot up--XP Pro

I have a friend who suddenly couldn't open Internet Explorer at all and only
got the "Send" or "Don't Send" error report thingy every time and he also
had some kind of security problem when he tried to run Netscape instead so I
ended up formatting and re-installing XP for him. After installing the
operating system I then went ahead and installed sp1, Norton AV, Zone Alarm,
and several other applications. After thinking all was GOOD all of a sudden
it takes at least 10 minutes for the computer hard drive to stop cranking.
It takes 3 or 4 minutes for the start button and clock to come up.
Sometimes it reboots itself during this time.

So anyway, I start looking at the processes running and try to see what's
going on. The only thing I question is that during this time explorer.exe
seems to take up a lot of the CPU processing time. I don't see anything
else going on. This did not happen before I formatted and this is the same
setup that he had on there before.

Computer Stats---800mhz, 128meg RAM, 40gig hd

Thanks for any help...