[2020] Installing from one pc to another

After installing Uplay on the other PC, you can copy the whole installation folder of the game to that PC.
If you then open your games library and select Anno 1800, there's an option to locate an installed game:

Uplay will then check the game's files to make sure they're complete (if not, the missing/broken files will need to be redownloaded) and if all is good, you can start the game.