c# - open WCF svc file error in IIS -

I am using VS2010 + C # + .NET 4.0 + IIS 7.5 + 7. When I open a WCF svc file in IIS 7.0, there is an error like this, any ideas that are wrong?

The system. BadImageFormatException: Could not load one of the files or assemblies 'foo.test' or its dependencies. Perhaps the application pool is configured to target CLR 2.0.

You need to target it on the net. 4.0:

Also make sure that. NET 4.0 is registered at:

 % WINDIR% \ Microsoft.NET \ framework \ v4.0.30319 \ aspnet_regiis.exe -i