As of this writing, the Dota 2 game is over 8GB in total size, which takes some time to download everything to one computer alone. With future updates inbound, no doubt the overall size will only get bigger. So if you’ve another computer that you want the game installed into, it’s simply better and faster to just copy or move Dota 2 to this other system from another PC. The guide below will show you how it’s done.
Copy everything in the Steam folder
Go to your Steam directory/folder. By default, it’s located in C:\Program Files (or C:\Program Files (x86) if you’re running on a 64-bit Windows operating system).
Copy/move everything in the Steam folder into an external drive or a removable flash drive to move it to the other computer.
Run steam.exe on that computer to let Steam reconfigure its settings on that new system.
The bad thing about the method above is that all other games downloaded through Steam will also be copied/moved, meaning it’s not just over 8-15GB you’ll be handling with but most likely and significantly more than that.
Moving only Dota 2 to another PC
If you don’t have Steam on the other computer, copy everything except the SteamApps folder. Afterwards (or if you already have Steam on the other computer), go to Steam\SteamApps\common and copy the dota 2 beta folder into the common folder of the other computer.
This method is also applicable to selectively moving/copying other games in Steam.
Update (February 21, 2015): Remember to copy the file appmanifest_570.acf in the Steam\SteamApps folder to the other computer. Copying Dota 2 may still require a bit of download when you launch the game, but with appmanifest_570.acf the size to download is smaller.
Why copy Dota 2 files instead of reinstalling? For one, a backup using this method is more convenient. Even if the files you’re copying belongs to an older version of the game, Steam will only need to download a few more files to get the game updated, instead of reinstalling everything (of over 8GB in size) from scratch. That said, the newer the version being copied, the better.
For another, this is probably the fastest way to distribute the game to multiple computers, especially ones set up for local/LAN play and systems belonging to an Internet café. Consider this as the best way to install Dota 2 without downloading the whole game and technically without the use of Steam.
Note that this method for moving Dota 2 and other Steam games can’t be used for piracy, because these games can only be accessed by Steam accounts that bought/signed up for those games. Unless you replace some files with cracked, you won’t be able to play them besides the official way. I won’t tell you any further about this, as it is illegal. You just got to know where to look for these illicit files yourself.
Though free, it may take a while for new players to gain access to Dota 2, the wait duration of which largely depends on Steam’s discretion. While you wait, you can copy the game already and be able to play almost instantly when access is given.
Should some problems arise when you attempt to run the copied game, go to the Steam dashboard, right-click Dota 2 in the game list of the Library section, and click Properties. Under the Local Files tab, click Verify Integrity of Game Cache, let the process finish, and try running the game again.
If you don’t have another computer to copy the Dota 2 game from, you can always go to the official website, sign up for an access if you haven’t, and download it through Steam. Depending on your Internet connection, getting the game up and running may take a while. Better read more stuff, such as where to get free Dota 2 items, while waiting.