If you are getting this error:
'%1 is not a valid Win32 application'
Try running the following:
c:\inetpub\adminscripts\cscript adsutil.vbs set w3svc/AppPools/Enable32bitAppOnWin64 1
Additional Comments
The setup of this program under IIS is NOT supported by tech support and those who choose to run WC under IIS must be aware of all security issues and ramifications of running any applications under IIS. It is recommended that all Patches and updates be installed on IIS before the installation of WorldClient as an ISAPI extension.