step1:-
in Add Script Map dialog enter:
Request path: *.wgx
Executable: C:\Windows\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll
Name: VisualWebGUI-Page
Then click Request Restrictions…
Clear Checkbox: Invoke handler only if request is mapped to:
Click OK
Click OK again on Add Script Map
Step2:-
Change the application pool to classic.net apppool at basicsettings tab in under Actions menu.
Step3:-
give iis_iusers read permissions for web.config

just execute folowing in cmd prompt (run as administrator):
c:\windows\system32\inetsrv\appcmd.exe migrate config “site-name/app-folder”

I notice IIS 7 includes a handler mapping for .exe.config to text/xml, but I’m still amazed that these two different Microsoft technologies don’t work well together.  It seems like blocking web.config, application*.config, etc, still doesn’t need to block *.exe.config.
how on earth I can get IIS 7 to serve *.exe.config files?
A:
Global by:
%windir%\system32\inetsrv\appcmd.exe set config -section:system.webServer/security/requestFiltering /-fileExtensions.[fileExtension='.config']
Per domain:
%windir%\system32\inetsrv\appcmd.exe set config [...]