Many people load presets into FL Studio generators/instruments by clicking the "Plugin options" then selecting "Presets". The disadvantage of this method is that once you've selected a preset, the list disappears - so to load a different patch you have to go through all the clicks again.
In FL Studio 6, there is a faster way to browse and select presets for generators using the "Browse" menu. I've listed the steps below and provided an image of the process as a reference (click the image to see a larger view).
In this example, I've loaded the Wasp XT into a channel in the step sequencer. I clicked the button for the generator which launched the Wasp XT window.
In the top left corner of the window, click the "Plugin options" icon (Step 1) , then click "Browse Presets" (Step 2). This will cause all the presets for the generator in question to magically pop-up in the browser window on the left. Now you can see all the presets for the generator in question. To load a preset into the generator, simply drag from the browser to the generator (Step 3).
I hope you found this little tip helpful. Checkout our FL Studio Video Tutorials for more detailed instruciton.