Ripper64, thanks for the work around. As I mentioned, I had no problems with my Vista x64 desktop, but got the failed install message on my Dell I9200 XP Professional laptop.
There is a similar file (sxuptp.inf) for Windows XP in the install "Files".
Do you know what is the equivalent of "Add Lagacy Hardware" in XP? Or what driver would I update? The literature on sxuptp seems to indicate it is a "keyboard" driiver??
BTW DIR655 Tech Support so far as only asked me to try again.