That's not a very specific question. Steam can play on any computer Windows XP and onwards, and also works on a Mac. Windows 7 or maybe Vista are reccomended though. Most games take up 5-12 GBS so make sure you have room to spare.
If you have another computer you can install steam onto that one and re download the game but it will not allow you to duplicate the game because thats illigal copy and violates your agreement with steam. So only one person can have the game on one machine so if your buddy wants to play with you he will have to set up his own steam and get the game. You can purchase the game and send it to him as a gift on steam one of the cool options they allow to share a game but you still have to pay for it unless its free
un-install the game and then you have to re-download it from steam , it then updates itself and you should be ok to play it after that.
Steam automatically pauses downloads when you run a Steam game so the only option is to play a non-Steam game (something outside of Steam).
no it doesn't need steam
Yes, as long as your computer meets the minimum requirements. Just launch the game from Steam.
As of a few days ago, Valve software released it onto their Steam Distribution system in the free to play section. What this means is that as long as you have a computer capable of running steam and you have a steam login, you can get the game from the steam store for free.
Yes. You just need to know their user and password then log in and you can install the games. Do note that this is a violation of the user agreements and could result in penalties and even criminal charges. You are essentially depriving the company of revenue.
Did it install with steam? If not that is probably why. Go to www.steampowered.com and download steam. When you installed it and registered an account, open up the client and click the game menu in the top left corner click activate a game. Then enter your serial number that came with the game.Steam connects all your games to your account, so that you can play any of your games on any computer you own.
You cant play with 2 people locally, however if your friend has a computer and can run team fortress 2, you can create a LAN game and invite him through Steam.
You have to download Steam on your computer, then Left 4 Dead 2 can be bought from that.
As long as you play through reputable sources you will be safe. I.e. Steam.
You can't play PlayStation games on the computer. It is just not possible at all.