>Not sure what version of IIS I'm looking at at the moment but the only place I see to set the .NET framework version is, as above, from the Web site properties on the ASP.NET tab. Don't see any similar option for an Application pool at all ?
>I also don't think you can vary the .NET version for a virtual directory - it's fixed at the Website level....

The PC is now under Windows 7 64 bits with IIS 7. The interface is completely changed.

Basically, I am now allowed to have application pools locally. In it, I can select the .NET version. At the Web site level, a virtual directory in this case, I cannot find a place to go in any ASP.NET setting.