That machine ran Windows 8.1 quite nicely at one point actually, you wouldn't believe it. That said, if I was to set it up now, I'd probably stick with XP just for the same of compatibility. Not like the stuff I play would even need an Internet connection.
Current gaming machine is another old laptop, one I'd got from new, which I've put in a bureau and connected a monitor and external HDD to (for films) and bluetooth keyboard/mouse and a USB SNES controller.
Yep, you guessed it - "gaming" in this instance means I've got a pile of emulators on a computer that would otherwise end up in the bin.
The ambiguity with the term "gaming" gets on my tits as well. I mean some emulation, maybe UT, maybe Minecraft, possibly even AoE. My brother would mean FPS on his PS3 (if he's still got it), and my father would mean a deck of cards.