I too downloaded the service pack and at first, my printer wouldn't work. Apparently I need a new driver update, exceot Canon hasn't issues one yet for my dinosaur.
But then this am, after trying to correct the driver issue, when I went to reboot, it froze.... unplugged for 10 sec, rebooot, same deal. Took six times to get rebooted, at which point I decided to remove the service pack and wait until they get the lead out. Now it works just fine. Printer too.
Funny thing though, I had Windows 95 for the longest time, Everytime they upgraded, I stuck with what I had, and never had a problem with a virus, except once with the Klez worm, because hackers were all keying on the newest version.
Makes me wonder if I should just stay with what I have until it's time for a new computer again.