StyleCop is a useful tool that helps development teams establish coding standards per Microsoft best practices. Unfortunately, you will likely be inundated with hundreds of warnings if you run it on an existing codebase. I recently ran it on a solution which I inherited and Visual Studio displayed 1000 warnings. There are likely more and 1000 is the Visual Studio limit.
Here is a nice post on how to exclude files from being analyzed by StyleCop. By implementing this process, you can have StyleCop analyze only new files, which will hopefully lead to faster adoption since you won’t be confronted with hundreds of warnings at the outset.