This seems to be a common problem. Here's a link to a Microsoft article discussing various causes, and some actual fixes.
these 2 are probably most relevant :
1. Another Windows Installer-based Setup program is running.
2. Windows XP is damaged.
From what I see with this issue - After WinXP is completed installing, don't do any other type of installs; updates; other looking around, etc, until running the drivers installs. If the driver install seems to 'stall', move the frontmost window to one side to make sure that another window is not behind that one, waiting for input, and preventing the rest of the install.
My first thought with your symptoms is to suggest that you start over by reinstalling WinXP. Choosing a Windows repair from the beginning of the XP install might be good.
Or, find some local kid who has reinstalled Windows a lot.
darn windows, anyway... is it really worth the struggle?
Serendipity is a lucky guess !