I have an old 2006 Macbook that i want to repurpose for my older sister, but having troubles with the reinstallation process. The discs are no where to be found. How can i go about with the reinstallation? But i'm wondering could i install Mountain lion instead, and if so how? It has a 2.0 GHz Intel Core 2 Duo with 4GB of DDR2 Memory, would it be advisable to run Mountain Lion or go to 10.6 or 10.7?