In case anyone else encounters a several-minute hang while booting,
here's the solution I found--

My family's computer, a P3 1.2GHz with a 64MB MSI GF3 Ti200, developed
an irritating problem where it would hang during bootup for minutes at a
time (2-5 in my experience, but they say it was sometimes as long as
15). After scanning for viruses and removing dozens of items from
startup, I couldn't fix it. Then I tried updating the video driver.
After removing 41.09, it booted right back up. But after installing
53.03, the delay came back.

A 4MB PCI Virge card I had lying around didn't have the problem, even
with the appropriate video drivers isntalled.

So I tried flashing the card's BIOS, with the 3.20.00.19 BIOS he
(There are newer ones, but they didn't match the TV encoder chip type.)

http://whitebunny.demon.nl/hardware/chipset_nvidia.html

And, what do you know, it worked! After reinstalling the drivers (since
Windows thought the card had changed), the boot delay went away.

(FWIW: I had to use the -6 option in NVFLASH to override the PCI
subsystem ID, since the reference BIOS uses 0 for generic...)