yes just go to browsing history by clicking crtl h and click import
All of the games that you have paid for with your account will still be on your steam name even if you delete steam or reinstall your computer. Install the steam again and log in with username/email + password and all your games will be in your library again you just have to redownload them all over again.
yes if you have steam account and you have purchased games with it. You can log back into that account if you reinstalled your computer or what not and log into steam again with that account and have all those games still in there just have to redownload them :(
You shouldnt have to. When you download the content, it will store it on your hard drive memory. Test you hard drive by saving games, demos etc on it. If working, your hard drive is fine.
well you put the disk in select computer and double click the disk drive D: you can get steam games with virtual disks so you will never need one if you purchase the games from their steam online store.
If you delete your DSi store games, you can redownload them from the DSi store itself.
Download the latest update, and redownload the games from the PSN.
No, games need to be installed locally onto the hard drive of the computer you wish to play it from.
You can simply redownload them from the PlayStation Network.
If the game is available On Steam (See links below) you can add the CD Key/serial number by selecting the Activate Product On Steam from the Steam Games menu. Otherwise you can try the Add Non-Steam game option which may or may not find the game in the Mac's drive.
Yes you can, you import and add non-steam games to your Steam library. From within the library you can launch and run any games, although 'Steam achievements' will only be available for Steam enabled games.
They don't. Only games distributed and managed by Steam can make use of the Steam API.
Yes, some. Not all of them can be activated on Steam. See the related links for a list of the games that can be activated on Steam and for the instructions on how to activate a game on Steam.