I found a handful of comments on the PC version's box and DRM while reading a review. It seems like the decision to drop DRM was made very late in the day, after the box had already gone to print. I'll quote the comments over for you:
Poisoned Sponge: I checked the box of the PC version of PoP today at work, and it says that it requires at least the disc and a cd-key, so it’s definitely not without DRM, but there’s a chance that’s all that there is.
The package designers didn’t get the memo it seems. I own the retail box version, and while the box states that the game “contains technology intended to prevent copying”, I can confirm it has no DRM whatsoever, not even a disc check. Part of what sold me on the game. Goodness knows I’ve saved enough money skipping Bioshock, Mass Effect et al since the current incarnation of Securom pitches a fit when trying to read a disc off my DVD drive.
Link: Installed it, put away the disc, and played it on a completely offline PC with no issues whatsoever. Even made a backup disc, and I haven’t done that since the days of Planescape.
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