I've recently purchased an HP PC with XP Home pre-installed. After experiencing some set up problems with my non-XP approved DSL modem I was told that there should be an 'Application Restore' option.
As this was not available I had to do a complete system restore and lost all of my data in the process. I had no choice but to follow this route as both HP and my ISP were unable to resolve the issues. I wass advised that my Modem manufacturer, Fujitsu, does not provide XP certified installation disks.
The only way to solve this conflict if upgrading to XP is to download the updated XP drivers from 'http//click here' then uninstall the Modem software the re-install.