1. Locate your Steam Directory & DayZ folder
2. Double click on DayZ_x64.exe to boot game OR right click on DayZ_x64.exe and use "Run with graphics processor" command.
3. Error window stating "Unable to locate a running instance of Steam" pops up
4. In task manager window you can see the 64bit version loaded however no CPU resources are being used.
5. Because of this error the game loads the 32 bit version instead.
6. Game runs normally.