Nice one

You can't, he already used it

L O L

try writing to steam support, there's a minimum chance to get the gift back, but it's worth a try

replace the key for the key steam steam

thats why u need to check system requirements first.

Even if you could get it back, it sounds like something that has to do with the computer or something. Having it in your account does nothing but link it to you and give you access to downloading it, essentially. He should make sure his system meets the requirements and try re-downloading it.

I gifted some bubblegum to my friend, but when he started chewing, he realised he doesn't really likes strawberry flavour.

One of the funniest topic on SG so far.

Rather than getting it back from him, he might want to fix his crappy pc instead because
A) the game is awesome
B) that game engine will run great on almost anything, so if it doesn't play then I'd take a guess that nothing else does either.

Try to write to Tripware support, I think the problem is fixable. KF is one of several Unreal based games, I don't think he can't run it.

i dont think you can

Sounds like your buddy needs a little dosh for a new rig.
money money money

Looks like he needs a fragging, a defragging