Enable or disable 32bit IIS6 applications on Windows x64 versions

Enable 32bit App pools on x64:
cscript %SystemDrive%\inetpub\AdminScripts\adsutil.vbs set w3svc/AppPools/Enable32bitAppOnWin64 1

Disable 32bit App pools on x64:
cscript %SystemDrive%\inetpub\AdminScripts\adsutil.vbs set w3svc/AppPools/Enable32bitAppOnWin64 0

thats it!