well, to me it really worths but still has some issues with compatibility yet still better than vista ...no way to compare as to your question sir, as to my info .... as long you run it on one computer no problem where you are using it on ...let's say just like kaspersky because to my info microsoft doesnt use HWID method
I would recommend Windows 7, I can provide you with a test drive on my PC via teamviewer if you want, as normally schools are very limited in terms of what you can access, at my school, everything is blocked/filtered except Microsoft Office, Internet Explorer and a few Macromedia programs.
In reply to your question on a home built PC, it should work in theory, as long as it has the required specifications. Click here for more information on the system requirements