[User23]

That's absolutely false under US law[1]. Once you have a legal copy, you are free to run the software without a license, including making additional copies for archival or as necessary to use it (for example, copying the program from disk to memory for execution).

The anti-circumvention statutes mean DRM complicates matters, but you definitely have a legal right to the game files themselves. For what it's worth, I believe that a competent lawyer could successfully argue that disabling DRM is an "adaptation" that's an "essential step in the utilization of the computer program." Get the case in front of Judge Alsup or some other computer literate judge and the argument would probably even prevail.

[1] https://www.law.cornell.edu/uscode/text/17/117