Copy the Steam folder using your network.

Steam sorts it all out. And when you run a game, it goes to download it, discovers it already has the files, and just sorts everything out.

if you have lan, you can copy over the library folder, though in order for each game to be registered with steam, you have to tell steam to install them. here is a better solution: copy each game over to an external harddrive connected to your old pc and then connect that to your new pc. that will automatically add all of your games to your new pc.

First have to setup the new PC then enable the network sharing on both PCs so you can see the other PC over File Explorer > Network and then can start with copy the Steam folder from old PC to the Public folder on the network PC. Once done, on the new PC you just copied to, go to C > Users > Public and move the Steam folder to C Drive. Once tbat is done, go to C > Steam, right click Steam.exe > share to > make desktop shortcut. Rename the desktop shortcut. Right click that and click Run As Admin

Originally posted by MastroRob:

What's the best way to transfer my Steam game library to a new PC?

If you have a semi decent broadband, then you can simply make sure all saves data is in Steam's cloud and then redownload it again on new PC.

grab gamesave manager, easiest way
disable steam cloud and ms onedrive

Originally posted by _I_:

grab gamesave manager, easiest way
disable steam cloud and ms onedrive

This but that's for the extra game files... your game config and save game slot files that gets scattered across Documents, AppData structures. GameSaeManager on the old PC and doing.a backup and then do a restore on the new PC will be an easy way to migrate the data needed for when you run your games and want the settings already configured and ready to to along with your single player saved game data.