So there's a big problem. Because I bought a Steam game that is about 25GB in size. The problem is that we have such a slow internet speed that the download process will take up to 3 days. Luckily I have a Windows 10 laptop with me, and we will go on a trip tomorrow, to a place where there's super fast public hotspot Wi-Fi. And that's why I want to do this, download this purchased Steam game via my laptop from Fast Hotspot WLAN, and then at home copy this downloaded Steam game into my PC, so that the Steam will immediately think that the game has already been downloaded, and which I can then start directly in the Steam library. Do you think something like that would work? If so, which Steam file do I have to copy?
Yes, you can choose which folder the games are in on Steam.
Yes it's very easy you take a stick or an external hard drive load it on it and then throw it over
Yes, of course, copy it to a USB stick and then connect it to the pc, but you still have to reinstall it I think
Yes you can! Download the game to your laptop (by default) go to Programs (x86) → Steam → steamapps → common → (game name) Now simply copy the game onto a USB hard drive or transfer it to your other PC (Google Homegroup if you want to do that). Just copy this game into the same folder on your other PC, as soon as you go to install on Steam, it should say "Checking files" and nothing needs to be downloaded.
If the message "Not enough storage space" copy all of the "appmanifest" files (depending on the number of installed games, it could be just one) in the folder Steam → steamapps → common. Then paste them in the same folder on your other PC, the game should now appear as installed. The only important thing here is that you have closed Steam when you do this.