An old game but wanted to add my report. This game works for me but required some tinkering. The problem is that when you launch the game normally from Steam in gaming mode, it opens 'Battlelog' a browser window where you then are to launch the game, however you get an error saying you're not using a supported version of Windows. There is a workaround that I found for Battlefield 3, that also works for Hardline. In Desktop mode.. Add the Firefox UA switcher to Firefox https://addons.mozilla.org/en-US/firefox/addon/uaswitcher/ Set the new extension to the first/top option for Windows Add Firefox as a non-steam game Switch to Gaming Mode Launch the game from Steam You'll get a web browser pop-up where you would then launch the campaign. Press the Steam button and launch Firefox. The game will be running in the background. In Firefox, navigate to/search for Battlelog for Hardline. You may need to login with your EA account. Get to the same page that you were in while playing the 'game' to launch the campaign, and launch the campaign. It should load since you are now loading it from Firefox, while the UA switcher is telling Battlelog that you're playing from a Windows device with the correct version. Press the Steam button, and switch back to the game (from Firefox). The game should now be loaded