How can I pass an installed game from one computer to another?

Explain like you're 5, eh ..?

Here, have a cookie and go outside and play. :X

Can you just plug the 2nd PC into the web and download it ...? Or does the 2nd PC not have any way to connect to the net?

Try this link

I'd use my flash drive.

A computer without the ability to connect to the internet? You can probably transfer it with a floppy disk.

You can do a copy and paste, Steam is smart enough to recognize the files are already there. It will still show a status as if it's downloading, but it's just verifying the files. Using the backup feature also works, but it takes longer because it will compress the files. Either way, do a verify game cache by right clicking the game in Steam, click properties, select the local files tab and press the Verify Integrity of Game Cache button to make sure nothing is messed up.

However, I believe you will still need internet access on the target computer since the Steam client needs to activate or register the game to the client to make sure you own the game. You should only need it when you install and/or the first time you run it. After that, if you put Steam offline, it will continue to work.

try copying your whole steam directory (without the games), i think the files linked to your account are there and you can launch the client in offline mode. then you can use the game backups you have

Could you physically pick up and carry the non-web computer to somewhere there is internet - or are the computers too far apart (eg. Greece and Cuba ?)

Some games have settings and files in many locations - just copying a folder from one computer to another will typically only work with the most simple of games. That is why many games have to be "installed" - to make sure all the other requirements and settings have been taken care of.

Hi. Without internet you can copy your game folder from one computer to another and overwrite some files with crack/nodvd, but it's illegal and you'll do it at your own risk. Profit! :)

copy the whole steam folder (yes, everything)

If copying the whole steam folder works, that'd be nice. Else all I can think of is copying torrent folders.