Cannot start service SPUserCodeV4 on computer

I encountered this error when I was trying to deploy a solutions right from within SharePoint 2010. It seems this is because a necessary service is not running. The particular service we are talking about here is called "Microsoft SharePoint Foundation Sandboxed Code Service".

To turn it back on:
* Go to Central Administration -> System settings -> Manage services on server
* Locate the service and turn it back on

This should allow you to again deploy solutions from within Visual Studio 2010.

Could not load type 'System.Data.Services.Providers.IDataServiceUpdateProvider'

Recently I was experimenting with an add-in for Outlook 2010 from where I want to do all kinds of things in SharePoint 2010. Therefore I wanted to make use of the /_vti_bin/listdata.svc Service Reference. When I tried to add the service reference in Visual Studio 2010, I received the error.

After searching for some time and checking assemblies and their versions, I came to the conclusion you have to install the latest version of the ADO.Net services. I found the latest version for Windows 7 and Windows Server 2008 R2 here: http://www.microsoft.com/downloads/en/details.aspx?familyid=79d7f6f8-d6e9-4b8c-8640-17f89452148e&displaylang=en