Source Control

Tools > Options - Source Control tab

Plug-in selection tab
SS

Solution.suo

Solution User Options
Binary file containing the solution user options (inc startup project(s), window positions etc)
This is a hidden file by default
This should not be checked in to your source control
TFS does not check this file in.

project.csproj.user

Project User Settings
Text file containing specific project settings
This is a hidden file by default.
This should not be checked in to your source control
TFS does not check this file in.