Installing : Installing System Architect XT : Enabling System Architect XT web service : Checking and configuring ASP.NET mapping
  
Checking and configuring ASP.NET mapping
1 On the Virtual Directory tab, click Configuration.
2 On the Mappings tab, locate the .asmx entry in the Extension column.
The Executable Path column for this entry should display:
C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll
3 If the .asmx entry appears and it contains values above for the Executable Path, click OK and then see Setting directory security.
If it does not contain the values above, System Architect XT web service was not mapped to the correct version of ASP.NET. In this case, click Cancel to return to the Virtual Directory tab. To map the System Architect XT Web Service: see Registering the .NET framework.