Some server do not have “Microsoft .NET Framework 2.0 Configuration” in there administrative Tools

they can use CasPol.exe to Fully Trust a website.

Please run the following code in command line.
%windir%\Microsoft.NET\Framework\v2.0.50727\caspol -quiet -m -ag All_Code -url “http://localhost/*” FullTrust

 

you can also download .NET Framework 2.0 Software Development Kit (SDK) to install  Microsoft .NET Framework 2.0 Configuration

and you can trust a website using the GUI  like below

 

1.     From the Start menu, point to Administrative Tools, and then click Microsoft .NET Framework 2.0 Configuration.

If you don’t have Administrative Tools on the Start menu, from the Control Panel open Administrative Tools, and then double-click Microsoft .NETFramework 2.0 Configuration.

2.     Under My Computer, expand the Runtime Security Policy node, the Machine node, Code Groups node, the All_Code node, and then right-click the All_Code node and click New to open the Create Code Group dialog box.

3.     Name the new code group 'MY WEB APPLICATION NAME', and then click Next.

4.     Select a ‘Site’ membership condition from the drop down box

5.     Under ‘Site name’ type in  the URL to my web application

6.     Give ‘FullTrust’ permission set and click Finish

7.     To apply the new settings, close and restart your browser