I realize you've solved this, but I wanted to contribute the solution that I found when windows update stopped working on me. If you're on a win98 box, and your date is set incorectly by years (in this case, a bad bios of some sort) windows update will report that there are no updates available. What it's really trying to tell you is that the SSL certificate was rejected, but it doesn't come right out and say it. This took me quite a while to figure out...

Matthew