Throw away your Vista discs; Geometry Wars: Retro Evolved is coming to Windows XP this Friday, via Valve's download service Steam.
On the mouse and keyboard side, the Bizarre Creations shooter was originally one of the big hitters in the Microsoft's Windows Vista-only casual games.
Now though, you can pick it up for the stupid pirce of $2.50 (yes, £1.25) - though admittedly you're not going to get any of the achievements Vista offers. Achievements, lovely, lovely achievements...
"With over 13 million active accounts, Steam is the ideal platform for launching Geometry Wars: Retro Evolved for Windows XP," said Martyn Chudley, Creative Director at Bizarre Creations. "We hope to continue the success of Geometry Wars by introducing its award-winning gameplay to one of gaming's largest communities."
Seeming as you're going to have some money left after this purchase, you might as well have a look at the upcoming Wii and DS versions.
Steam, for you download rookies, can be picked up here.