Windows 2008 Server/ .NET Support

We have a Windows Hyper-V 2008 Server with lots of small 'cloned' websites running on it. Each website runs on IIS and connects to a SQL Server DB on another Hyper-V server. The problem is that many of the sites error - with an Exception of type '[login to view URL]' error. We have rebooted the server - and this intermittently fixes some of the sites - but the problem persists throughout our websites (which is not ideal). All the sites have worked in the past? I am looking for someone who understands this error - and the causes - and can investigate and fix the problem on all sites on this server (the solution will replicate across sites - as they are identical). I have attached [1] Screenshot of Error for one of the sites [2] Screenshot of Event Log on Server - showing ALL errors/warning [3] PDF of event log error message for this one site I am not a server expert - but need someone who is. On the successful completion and rectification of this problem - i am happy to discuss a longer term retainer to help support the server.