Ok, so I have built a Dll and a Windows Service in vs2010. Both are targeting the .net 3.5 framework, but when I install it on the server it installs fine, but for some reason it targets the 2.0 framework and any time the methods fire that are using linq it crashes out with a clr20r3 error system.nullreferenceexception. Not really sure why it's not targeting .net 3.5. Anyone else had any issues with deploying a .net 3.5 service on Server 2003?