DIS is also a Unix based product and that is why it has to be run under VM. The XP laptop/VM Host was the only compatible option at the time to run the Unix VM (as per 4.8isX5 states too).

These days, you can use Windows 7 and 8 (both 32bit and 64bit.. I do with DIS) and it works 100% the same as running it on XP (under a VM environment)

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2005 3.0D, Black on Black.