It is not possible to choose the needed ASP.NET framework for your virtual directory in IIS. This again causes errors loading the pages.
.NET framework is installed before IIS is.
On IIS5/6 based systems (Windows XP, Windows Server 2003) by default .NET Framework 2.0 / 3.5 are missing. When you install it and if IIS is present then installation should integrate the .NET 2.0 / 3.5 support for Web Applications. As these versions of Windows were released before Framework 2/3, they can’t integrate the Framework to IIS when you install the IIS role after Framework installation. It means that Framework 2.0/3.5 seems to be installed but you can’t choose it for IIS Web Sites.
Reinstall .NET Framework, you can use the tool “aspnet_regiis.exe" for that purpose.
Framework 3.5 is expansion for Framework 2.0. So when 3.5 is installed then you choose anyway 2.0 version for IIS Web Site and integrate it to IIS the same way as you integrate 2.0 version (on IIS6 based systems).
Read also: http://msdn2.microsoft.com/en-us/library/k6h9cz8h(VS.80).aspx
IIS versions: 5.x, 6.0
AxCMS.net versions: All versions