is it possible to install another version of windows on a computer running win95 using the windows disk I received with another machine, and if so, how do I go about it? Or will I need to purchase an upgrade? I have an oldish HP Vectra which I would like to upgrade, but it is running win 95. There are 2 partitions on the hard disk 1.99Gb each. I have formatted the one without the OS on using windows explorer. Can I go any further without buying an upgrade disk? It might seem a bit tight fisted, but I have this disk here with a perfectly good OS on it, and a legitimat product key. If I can use that, it would be a few more pence towards memory upgrade costs at least! Or am I suggesting something illegal? thanks.