Download the full installer to a thumb drive. Then pass the drive around.

Download Firefox Full Installer For All languages And Systems {web link}

По этой схеме нужно на каждом пк запускать инстолятор. а хотелось бы настроить один раз путь к обновлению, откуда в дальнейшем будет закачка.к примеру как база данных касперского

If the computers you are talking about share the same network, such as a job site, you can place the installer in a common folder. Then each computer could access that folder for the installer.

If you want to have each computer get the installer automatically, that can be a bit more complicated.

• 1 Have a program check the common folder for the update, and install it if there is one (but not if it is the same as what is already installed.
• 2 An operator on one computer can send instructions to another computer. Once an update is found, the one can tell the others to update.