Things You'll Need
Instructions
Install Mass Effect PC as normal to the default directory. Without an internet connection, normally you would not be able to start the game as per SecuROM's code.
Download and unzip "removal_tool.zip" to a location of your choice. Run "SecuROM Remover.exe" and accept the EULA. This will remove all instances of SecuROM code that are allowed to be removed by the publisher. Mass Effect is one of these instances.
Run Mass Effect from the Start menu or the executable in the installation folder. The game should start up normally, with or without an internet connection.