How do I install ReSharper for All Users on current PC?

Run the dotUltimate installer, click on the Options button and select Install for all users on this machine:

In some corporate environments, installations of programs into user profiles are not allowed. In this case, you can install the desired JetBrains .NET tool into the 'Program Files' folder and thus make them available for all users on the current machine. This installation mode is not compatible with existing installations in user profiles. That is, if there are any JetBrains .NET tools installed in user profiles, you need to uninstall them before installing into 'Program Files' and vice versa.

To generate a Command Line to install the products this way via CMD, tick Administrative mode checkbox as well.

For more information about Machine-Wide installation, please refer to Installation for all users of a computer.