Borrowed WinXP Pro *service pack 2* install disc and tried installing Windows again. Good lord was it easier. (My old disc was SP1.)
The wifi card driver I got from the wifi card manufacturer website installed correctly the first time and I was able to get online. Now I"m updating Windows and installing Firefox.
So I have finally arranged things as I wanted: Windows XP Professional, Ubuntu, and a partition for data, formatted as NTFS. As much as I like the idea of Linux, it is good to have XP to fall back on for things that I can't figure out in Ubuntu. And a clean install of XP Pro with plenty of space and RAM is pretty zippy and nice to use. And I found out about a nice program called
windiff which I'm using to make sure all the files from my old hard drive got transferred to my new one correctly.
I think I'm gonna try to keep using Ubuntu most of the time, though.