I have an XP machine that actually runs City of Heroes, while my Windows 7 does not.
However, I use my spouse's Windows 10 rig for Homecoming, since I can multi-box on it without any slowdown.
It was, however, an ABSOLUTE pain in the ass to track down all* the "phone-home" mechanisms in Windows 10 and nuke or neuter them. Bastards are getting real wily, with both obvious and subtle back-up operations and processes designed to revive Windows Automatic Update. Medic's the obvious one, but there were two more under-the-hood processes which also needed to be tanked to stop WAU from getting re-enabled.
* I'm still not even sure I've managed to get them all at this point. Stuff like "Cortana" being integrated in the Windows Search Function made it extra difficult to strip out the parts that were contacting Microsoft, while maintaining my own ability to search for files on my own computer.
At this point, I really, really should just learn to use Linux. Windows is friggin' ridiculous.