EA limits Dead Space 2 to being authorized on a maximum of 5 computers at a time. The games must be authorized on a computer before you can play it, but you can have the game installed on any number of computers as long as only 5 at most are authorized at a time. De-authorizing the game on a computer does not uninstall it.
To de-authorize the games on a computer, simply uninstall it, or follow these instructions:
Some versions of Dead Space 2 may conflict with LucidLogix Virtu graphics switching software which may appear to be an activation error. After the software is installed when the user attempts to launch the game an activation software comes up after activating successfully it's supposed to launch the game executable, but the lucid virtu software will prevent it from doing so without issuing an error, which can make it appear that activation is the problem. Removing the lucid virtu software or disabling it when running Deadspace 2 can resolve the issue.
The latest updates of Dead Space 2 includes a piece of DLC that unlocks better armor and all the weapons at the start, thereby negating the need to find schematics and decreasing the difficulty. It's recommended for full effect that on the first run through you play without this DLC. To remove this DLC, you can download the original .exe here.
Simply make a backup copy of the currently installed .exe, download the old .exe, and copy it to the Dead Space 2 folder. If you switch to the old .exe, you'll also need to reset the keybindings to default.
You'll then be able to play the game without the extra unlocks. However, it recommended that you use the newer .exe for subsequent play-thoughs, as it properly unlocks some bonus items that you normally get for completing the game.
(The Origin version also includes the DLC now, and replacing the .exe no longer works.)
There are four special rooms in the game that are unlocked by completing the Dead Space Ignition tie-in which is not available for Windows. With a few files these rooms can be made available. Check out this forums post for full details: Unlock Conduit Rooms.
Normally upon completing the game on Hardcore or Zealot difficulty, you would unlock a special suit. Unfortunately these suits don't unlock properly, unless you happen to complete the game in a single play through. Details on unlocking each suit can be found here.
Occasionally with certain USB controllers or devices, the mouse will fling to the far edges of the screen, preventing proper aiming. To solve this, try:
%LOCALAPPDATA%\EA Games\Dead Space 2
Game falls into BSOD on different occasions, either randomly or at some particular point in the game.
Rollback to older driver version (Such as Catalyst 12.6)
Occasionally, when starting the game on a newer system, the main window will minimize itself and will not let the user restore it. To solve this, do the following:
Window.Fullscreen = true
Window.Height = 1200
Window.Width = 1920
where Window.Height is your desired height and Window.Width is your desired width.