Android SDK manager won't open

Make sure your java\bin directory is in your path statement before the windows\system32 directory. The SDK Manager uses java and it was finding the one in the system32 folder.

In a CMD window, you can run 'where java'. Don't forget to restart your CMD after changing the path variable for checking.

Alright, I had the same problem, and none of these answers worked for me (I'm running Windows 8). I tried running tools/android.bat and noticed I got some errors there. I investigated further and it seems there is something wrong in the code that finds your Java path.

This is how you fix it:

1. Open up tools/android.bat in your favorite text editor

2. Search for this piece of code:

   set java_exe=
   call lib\find_java.bat
   if not defined java_exe goto :EOF
   

3. Replace it with this:

   set java_exe=D:\Program Files\Java\jdk1.7.0_07\bin\java.exe 
   

   where the path is the path to your Java exe.

4. Run android.bat

(in my case I had to specify the path to java_exe in step 3 with no quotes to make it work.)

There are many reasons as to why the SDK Manager won't open. Rather than trying each one of them blindly, I recommend running the android.bat in a command window so you can read the error message and apply the correct fix.