I followed the instructions on ADT Plugin for Eclipse but I got this message when installing in Eclipse:
Cannot complete the install because one or more requ
Installing on 3.7 Indigo, I found the plug-in is now called:
WST Server Adapters
org.eclipse.wst.server_adapters.feature.feature.group
I finally followed the instructions on During installation, there's an error about requiring org.eclipse.wst.sse.ui. How do I fix that? and installed Google Plugin for Eclipse Galileo, then the installation of Android ADT Plugin worked without any problem, finally.
If anyone is upgrading from eclipse 3.6 and they've copied (overwritten or merged) their directories you will get a conflicting dependency error and ADT won't install. Make sure you go back , delete eclipse, unzip the new eclipse fresh to the new location and run it! Worked for me!
I got the same message in Galileo then I installed Indigo and it worked although I checked only dev tools and plugins the other two I didn't install and had some error with those. But the ADT works now.
On Windows 7, run Eclipse using As Administrator.
PS: I made it in conjunction with other advices like adding Indigo release URL to available sources and using HTTP instead of HTTPS, and I didn't tested if all three requirements must be met or the first is sufficient.
On ubuntu 11 it installs Eclipse 3.7 (indigo). To make it work i had to add http://download.eclipse.org/releases/indigo to the list of sources. After that it worked like a charm.