While everyone who went out and bought boxed copies of Modern Warfare 2 will be playing Infinity Ward's much-anticipated shooter, those that downloaded it via Steam will have to wait until Thursday

PC Gamers with a boxed copy of the game can activate it as of today, however, despite the fact that the two share the same DRM. Valve hasn’t commented as to just why Steam customers have to put up with the delay, perhaps they wished to avoid a huge download bottleneck. But with everything else that has happened with the PC version, it’s sure to mean another set of unhappy PC players – and the news isn't likely to help early day sales on the format.

Modern Warfare 2 was released worldwide last night and the official UK launch was hosted by Vernon Kay in London’s Leicester Square – the first time a game has launched in the famous Square.

[via Steam]