I am new to android software development. When I try to write the first android program, a pop up window shows up after I finish choosing all the basic settings, said that i
The SDK is bundled with Android Studio, you don't have to download it separately.
I've seen this issue on both machines I've installed Android Studio on - the "add-ons" directory doesn't get created at install.
Assuming you're on 64 bit Windows and installed to default location, look here:
*C:\Program Files (x86)\Android\android-studio\sdk*
If you don't have a "Program Files (x86)" folder, look in "Program Files"
I'd bet there's no "add-ons" folder in there. If not, create one and than start Android Studio. You should see no problems.