Don't delete this post, it is not a "do that to install without having bought the game" manual, it is "this is how you can install if you have the original DVD" manual.
I only registered to give this information instead of screaming "I have the same problem".
This is the DVD4 of ARMA X which is the ARMA OA DVD. DVD one to three don't have issues.
Things that don't make a problem:
Having Daemon Tools installed -> No problem. just exit the program and everything is fine.
Having an emulatied drive WITH the Securom option on -> No Problem, unmount all images and exit daemon tools.
The SPT (SCSI Pass Through) drivers -> No Problem at all.
Blindwrite 6.3.1.6: Blindwrite is not the problem, the sub component EZ-Play is what the copy protection hates.
So the solution is: Uninstall EZ-Play (or Blindwrite together with EZ-Play). Unmount any daemon tools image. Exit the daemon tools control program.
THEN it will install from the original DVD without any problems.