Try to attach INFINITY, and activate the cheats, after you have fully loaded the Game’s level.
First, launch the game by clicking on the .EXE file, which is BioshockHD, or Bioshock.exe, after you have renamed it. Else, you need to wait for the trainer author/dev to update the trainer, for the new exe.
Don’t launch the game from the STEAM client, use the above .exe file. Try to rename it to Bioshock,exe, and check whether doing this, makes the Trainer to detect the game ?
After that, once the game level has been loaded, just ALT+TAB back to your desktop and start Infinity. Click on the START GAME button to switch back to the game.
When the icon says “End Game”, this means the trainer has been activated.
You can only change the installed path, if you get the FIND GAME button prompt on top right side. If it says, “START GAME”, then Infinity has already detected the game folder.
Follow the same tips as mentioned before in this thread: