After I run the emulator, the window for it appears but it just stays black the whole time. What shall I do?

Hey Juan! I've had those similar issues. Are you using the newest release of Android Studio, with the updated AVD Manager? If not (or if you're using Eclipse), you should see an option when you're creating the device, to "Use Host GPU" in the Emulation Options (try enabling/disabling that checkbox). If you're using Android Studio Beta 0.8.12+, It seems they've removed the checkbox to select/deselect the host GPU, in which case, in your AVD Manager, under the "Actions" tab, you'll see a drop-down menu where you can select "Show on Disk"... if you edit the "config.ini" file in there, you'll see the settings: "hw.gps=yes" and "hw.gpu.enabled=yes". Maybe try setting those to "no" instead, and see if that works. I've had similar issues recently with the Android L x86 preview images. Hope that helps!

Thank you very much for such a comprehensive answer, Paul. It worked with the "Use Host GPU" thing for me, thanks!

Thank you Mr.Marino for quick respond, Actually I am using Android Studio Beta 0.8.9 and I don't knew how to edit the "config.ini" file

Hey , I'm just as new to this as you re I think. I faced the same issue with the emulator with the settings prompted by the instructor. I created a new emulator with new settings. Used nexus one instead. Try it.