Set the Microsoft .NET Framework version in IIS 6

If the Web Server is running IIS 7 then follow the instructions in Set the Microsoft .NET Framework version in IIS 7.

Step 1.   Open the IIS Manager (Start>Run InetMgr.exe)

Step 2.   Select the correct version of the web service and open its Properties.

Step 3.   Select the ASP.NET tab and pick the 4.0.30319 version

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Step 4.   Click Yes to restart, if asked.

Step 5.   Select the Documents tab and tick “Enable default content page” then close the properties