Object Browser has multiple "System" namespaces

Question

I am trying to use the System.Diagnostics.Process class, so I put the standard "using System.Diagnostics;" line at the beginning of my file.  However, intellisense won't show me the GetProcesses() method.  So, I went to the object browser, and there are two places that have the System.Diagnostics namespace, namely mscorlib and System.

How do I get Visual Studio to understand where the Process class is located so that it will show me all the methods when using intellisense ?

I tried adding it to my references, but it doesn't even show up in the .NET list.