Keep it. Play it once you upgrade someday. That's the easier and more effective way out.

Call it a loss and learn from your mistakes don't beat yourself up over it just be sure to check the specs next time before entering again.

I'm surprised your computer cant even run Portal

You must redeem the game. Trade or giveaway the games you win is against the rules.
Keep it in your library, when you get a better PC then you can play it. =)

If you already put the gift in your library, you're f-ed. But if not, keep trying to contact the gifter or after a week or so just start a giveaway with it. In the future, though, use www.systemrequirementslab.com to check if a game works before accepting a gift.

Trading it away or regifting it would look... suspicious. Not to say that your reasons aren't understandable, but without knowing the context someone (say, an admin) who sees that you won Portal, do not have it in your library, and then gave away Portal thus getting contributor points would at least raise some questions.

I'd suggest either asking support to reroll the giveaway you won (pick a new winner on that giveaway), or just accepting the gift. Chances are at some point you'll upgrade and be glad you've got Portal then. Heck, it's a pretty quick game so even if you've just got access to another comp for a little while you could play it.

Damn, what's your video card?

You could wait for the person to respond, explain what happened and tell them to ask for a reroll?

what are your system specs ?
You were able to play Bastion, so that's not too bad :)

keep it, sooner or later you'll get a pc that can run it.

I don't think you should be so harsh on yourself about keeping the game. i think most people wouldnt give a damn about it. maybe in the near future you will have access to a comp you will be able to play it.

Add it to your library. If you really can't use it, then give back to the gifter.

Either way, if your not going to play it or need it, don't enter to win it.

Give it to me

Hmm well on a completely unrelated topic, I see that you live in Kent... Hello from DuPont/Steilacoom :p

Buy a computer for 50 $ and it will most likely be much better than yours xD

I'd say take it, activate it and tell them by email / steam that you will play it once your computer is capable. I'm sure they will understand.

go to your grandmas house ans play the game on her computer which is so much better (what I do when my pc can't run the game)

activate and wait until you upgrade your pc. Game worth it.

lol do whatever you want

that's what I did

and now dey be hatin'