How to implement Abstract Factory for windowing systems

I was just starting a new coding project. I may be ahead of myself, but I've gotten kinda stuck. I wanted to implement an Abstract Factory for the GUI, similar to the example on Wikipedia. However various systems have their own parameters for creating windows. At present I have come up with the following solutions to my dilemma:

1. Create a type which varies based on compiler directives
2. Don't use compiler directives and just put everything in a type that contains every possible data member
3. Create a polymorphic hierarchy and use dynamic casting inside each window function
4. Use some sort of intermediate singleton that holds the information. This seems esp. unhelpful and would likely also involve casting.
5. Use a different pattern, such as builder instead.

My objective is to create high level interfaces that are uniform, so that creating a window, etc. is the same for all platforms.

I hesitate to do #5 simply because it seems like this would be a common enough problem that there should already be a solution. This is just a toy, so it's more about learning than building a practical application. I know I could use existing code bases, but that wouldn't achieve my real objective.

Thanks in advance.