I downloaded Dead Space from Steam today.
Back then I bought the UK retail version and activated it on Steam.
- My gaming OS is still Win 7 Ult. x64, game's version is the same as yours (v1.0.0.222)
- downloaded the latest Dead Space trainer for the Steam version into my trainer folder which has an exception in my anti-virus (the whole folder)
- as the instruction says, I started the trainer first with admin rights
- started Dead Space via Steam Client
- pressed F1 in the main menu of the game and got the "activated"
- until I got to the room with the first plasma cutter I haven't activated any of the trainer's options
- trainer is working as intended for me (tested only with health, ammo and stasis)
Maybe this could be a solution for you? -
Link.
Have you verfied the game's files via Steam? Or uninstalled it and downloadeded it again?
Otherwise I'm running out of ideas.