MainDQMClass.ListFiles(@"C:\Windows");
>Non static members can ONLY be accessed via an object (instantiated class) as in:>MainDQMClass mdqmc = new MainDQMClass(); >mdqmc.Connection = new SQLConnection(); >>If you want to stick with static methods, you'll either want to create and destroy the connection within each method (which I suspect you don't want to do), or add a connection parameter to all the static methods, create it in your calling code and pass it to each static method. Alternatively, you could make all your methods not static and just instantiate the class and it should run fine (which is maybe what your original intent was anyway).