[wix-users] Check Installed DirectX version

[Farrukh Waheed]

Hi
In Burn, how can we check the version of installed DirectX on any machine
before launching its installer?

Presently, I'm launching DirectX 11 installer and thought its installer
would do the necessary check, but it always install even if Directx 11 is
already installed...

 <ExePackage Cache="no"
                  Compressed="yes"
                  PerMachine="yes"
                  Permanent="yes"
                  Vital="yes"

SourceFile="$(var.PreReqDir)Microsoft\DirectX\2010\DirectX_June_2010.exe"
                  InstallCondition="VersionNT=v6.1"
                  >
      </ExePackage>

I need to improve its InstallCondition here to check if it is already
installed.
Thanks