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I'm deploying an ASP.Net web service to a VM running Windows Server 2008/IIS 7. I've installed the ASP.Net AJAX extensions (from here) on the server. However, when I attempt to access the service, I'm getting the following error:

Could not load file or assembly 'System.Web.Extensions, Version=, Culture=neutral, PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.

I've already tried restarting IIS with no success. I can see that the System.Web.Extensions dll is present (at C:\Windows\Microsoft.NET\Framework\v4.0.30319\System.Web.Extensions.dll), but ASP.Net somehow isn't able to find it. Is there anything else I need to do in order to get ASP.Net to recognize that this DLL is present?

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up vote 1 down vote accepted

It turns out that .Net Framework 3.5 is not installed by default on Windows Server 2008 R2. Running the installer for the .Net Framework 3.5 fixed the issue.

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