It's all along the same lines, with pointers allowing you to write directly to memory. If you've ever read about a PCs boot process, you'll know all about how different programs required for startup are written to certain locations in memory. And drivers do this as well. The program above wouldn't work in Windows because all the formats, etc... are different, but basically the same thing. If you need a control that's not standard in windows (like more than just a button or a drop-down menu) you'll have to do stuff like this to code it from scratch.