Bought Day Z.
Downloaded, wouldn't launch, it flashes up the launcher in steam then instantly closes.

Varified files, one missing, added it, no change
Deleted game, reinstalled, no change
Updated gfx drivers, no change
Updated Dx9, no change
Downloaded various dll files as 'fixes' from internet forums, no change
Tried running in -safemode, no change
Tried running in -window, no change

Exit steam. Find the common folder inside the steam folder and Day z, run the DayZ.exe, or DayZ_BE.exe and I get this error:
c:\windows\system32zd3dx9_41.dll is either not designed to run on windows or contains and error. Try installing the program again using the original installation media or contact your system administrator or the software vendor for support.