After looking at a dren load of support pages that were either in Russian or geek-speak, I downloaded FontAgent to check my fonts, which were all, of course, fine. So, then I removed a bunch of them from the font folder, and started up Photoshop 7.0. Wouldn't you know - it works fine. But all the fonts back in and was expecting another error. Nope, works fine. ImageReady works now, too.
Oh computer, how you like to frell with me.
Oh computer, how you like to frell with me.