>>>Then this defeats the whole purpose. I don't want the class to be created from outside my factory. I want to be able to set things
>>>on the instance before returning it to the caller.
>>
>>Then I think your options are limited. Either
>>(a) Create a CTOR for the class with parameters that accept the values you want to set
>>or
>>(b) Make the class private and hide it behind an interface.
>
>If you think of something like a DataReader. You cannot directly instantiate this class. You need a Command class to return a data
>reader. How is this done? Somehow they're only allowing the class to be created via the Command. There must be a way.

Maybe something like:

namespace Whatever
{
    public class MySQLDataReader
    {
        internal MySQLDataReader() { }
    }

    public class MySQLCommand
    {
        public MySQLDataReader ExecuteReader()
        {
            MySQLDataReader msdr = new MySQLDataReader();
            //Do whatever....
            return new MySQLDataReader();
        }
    }
}

Then from another assembly:

Whatever.MySQLCommand msc = new Whatever.MySQLCommand();
Whatever.MySQLDataReader dr = msc.ExecuteReader();
 Whatever.MySQLDataReader dr2 = new Whatever.MySQLDataReader();  //Compile error: The type has no constructors defined

>Could you elaborate on what you mean by " hide it behind an interface."?
Again in a separate assembly:

public interface ICustomer
    {
        string Name { get; set; }
    }

    class Customer: ICustomer
    {
        public string Name { get; set; }
    }

    public static class CustomerCreator
    {
        public static ICustomer CreateCustomer()
        {
            Customer c = new Customer() { Name = "Fred" };
            return c;
        }
    }

Then to create:

Whatever.ICustomer cust = Whatever.CustomerCreator.CreateCustomer();

First one probably best for your requirements tho....