Tartan Giant
Bad news, I'm afraid. When I booted the new machine off the WinXP CD it claimed that no valid O/S was found on the hard disk (preinstalled with Win98se) and wouldn't accept the recover CD as valid either.
However, it happily accepted my Win98 CD, so I guess that pre-installed versions of Win98 really aren't accepted. One thing that I didn't try was to boot into Win98 and then run the upgrade from the CD. That might still work.
First impressions are very positive, although I haven't run it for long enough to see how solid it is. It flies, but then again a P4-1.8GHz with 1Gb of memory should...