Yesterday, I was installing ADT for Eclipse. It all went well, until I clicked Check for Updates. After Eclipse rebooted, all the preferences are gone, I can't create new project, ADTs are gone. But when I try to download ADT from the Install New Software option, it says that I've installed it.
I've also reinstall Eclipse and same thing still occurs.
What can I do to fix this? I do not know what causes this whether it is ADT or Eclipse itself, because I can't even create new project for C++ or even Java.
I have Eclipse Indigo.
EDIT: I'm using Ubuntu 12.04