I am using Windows 7 and JDK 6.
I downloaded the package of Android SDK with Eclipse and followed the instructions to create the first Hello World application.
H
Me too had the similar problem. Struggled alot to resolve and finally this worked out for me.
Remove all the folders in the root folder of workspace(except workspace folder) like .android, .eclipse, .metadata etc
Save your platfoms to some safer place and delete the folder "adt-bundle-windows-x86-20130729"
Unzip the bundle again to some other locations
Try running the eclipse again and create an application
Run the application and see whether emulator automatically gets starting
Paste back ur platforms
This worked for me on my 4th attempt.