I installed 12.04, then I installed all updates in Update Manager. After this, I installed all the necessary applications and installed NetBeans 7.2. But now I am trying to launch it from Dash home and it does not start. Please help.
I installed Netbeans 7.2 on a clean new installation of Ubuntu 12.04 and found, that it was not available in the dash at all. But it should have created a link on the desktop. Try that one and lock it to the launcher if its running.
If that does not help you should try to start it from a terminal and find out, if the startup has any problems or errors in the output there:
If you chose to install it into another folder you need to change the path according to your installation path.