XP only allows itself to be installed with a previous "NT" install if "NT"'s SP6 is installed into the NT installation FIrst (at least on my newer-made-for XP-machine). This means that SP6 must first be on CD downloaded from the Microsoft site from a download-able OS prior to the XP install, ( I cannot get Internet Explorer 6 to load onto NT on this newer machine [ on my 1999/2000 machine NT and ME have all drivers in the factory image and work fine except that AT&T/Yahoo DSL does not download it's IE 6 Shell browser and thus no direct SP6 download]). I am spent on looking for NT drivers for this newer machine (NON ANYWHERE!!) and am now satisfied to get it to boot up with-out an internet connection and comparing it's files with XP's for curiosity purposes only-- very illuminating in comparison with each other. On this machine "ME" is grainy but "NT" is very sharp visually--One would expect both to be equally sharp, I would think. This is a HEADS UP that older machines perhaps should be kept if older OS's are to be used for whatever purposes --even if only for experimental reasons ( this goes double especially for printing purposes). Drivers are not 'built' or 'imaged' into newer machines as one would expect ( not expectantly here my pre- Leveno IBM can handle "ME" and "NT" [ even though it is an XP machine] with-out any graininess -- the drivers must be old enough to handle these). Windows 98 installs only if DD10 formats the partition previous to install !! This is very surprising to me as one would expect Window's formating would be better!! (contrarily the 98 install hangs on it's own formating procedure!!). These older Microsoft installs will be better left for dedicated posts in the future as more users are posting using these older Microsoft OS's partitions (thus dual booting) and their solutions (if any).