Differences would be a lot of installed software. Otherwise XP with updates running, e.g. fully up to date.
Computers run Kasperksy AV; I had not run a full scan in another computer, but I just started one (the host PC is also the test for Vipre AV, so we'll get a different opinion)
chkdsk run from a recovery console stalls out about 50% and, after leaving it running over the weekend, reports an unrecoverable error. It must be in an operating system file, because I was able to copy off the important data using another computer.