Afaik you can get refunds on pre-orders since you're cancelling it. Anything else not a chance.
No what YOU should do is check the compatability. Steam has no obligation to help out because of your stupidity.
what steam should do for future customers, is do a system check which confirms whether the game is compatible with your system and confirm what criteria you fit in. i.e. low spec = your system spec is low and you may experience slow gameplay ect/ or unfortunately your system does not match the system requirements and confirm why.
No what YOU should do is check the compatability. Steam has no obligation to help out because of your stupidity.
I suspect this applies to online sales teams as well, but to a lesser extent. No harm in trying to get your money back, is there?

. I fail at reading threads.