For the most part, the PC version of Dark Souls II is a marked improvement over the PC version of the first game, Dark Souls. The sequel looks great, runs smoothly, and isn't hindered by Games for Windows Live. Unfortunately, some new PC players are having a hard time getting it to run at all.
In a large and ever-growing thread on the Dark Souls II Steam page, hundreds of players are reporting that the game crashes at startup, and that as a result, they've been entirely unable to play. The game's developer Bandai Namco says it's aware of the issues and is working on fixing them.
A good number of the problems seem to be related to unique video card and monitor combinations, and the original post in the thread has shared a bunch of possible fixes for various video setups.
A second issue affecting some players appears to be blocking people flagged by Valve's automated anti-cheating system (called a "VAC ban") and keeping them from logging into the Dark Souls II servers. YouTuber Super Bunnyhop has been having the problem, and has posted a helpful breakdown of what's going on:
VAC bans theoretically block players who have cheated or altered files in various PC games, though they're also sometimes issued when players modify core game files to enable cosmetic graphics modifications like ENB filters, which aren't used for cheating. VAC bans are intended to only block players from the handful of games included in this list—note that Dark Souls II doesn't appear there, which means that players with VAC Bans shouldn't be getting blocked from playing it.
In their own official support thread, developer Bandai Namco says that the issue related to video cards "has been identified and the team is working on a fix." As to the VAC ban issue, they say that "We are aware of this issue and have escalated it to the relevant parties."
For my part, I've yet to have any issue getting Dark Souls II to run on my PC—the early access version I'd been playing for the last month runs without a hitch, and the retail version starts up fine as of this morning. But that's just me—obviously, these problems don't affect every player.
I've hit up Bandai Namco to ask for more information, and will update this post when I learn more. If you've been having problems playing Dark Souls II or have worked out any possible solutions, let us know in the comments below.
Update 4/28: The official support thread now says that "A fix is being worked on and will come in the form of a patch" for the video issues, and that they're hoping to release the patch "in the next few days." No news on the VAC ban issue, however.
Update 4/29: Bandai Namco says the patch has been released; still no word on the VAC ban issue.