The ASP.NET IIS Registration action allows the registration or removal of ASP.NET applications within IIS. It can also create ApplicationPools or get the status of the installed ASP.NET.
ASP.NET IIS Registration
ASPNET_REGIIS.EXE Command line options
Allows the selection of the .NET version to use for NGen. The minimum is .NET v2.0.
This options specifies as whether to force the usage of 64-bit tools on a 64-bit system or not. As FinalBuilder is currently a 32-bit application it will default to running the 32-bit version on a 64-bit system. Check this option if you require the 64-bit version to be run.