First and first, I had Netbeans installed on my laptop when it was on 12.04 but after I upgraded it to 13.04 and could not find it on my dash so thought it was removed on upgrade.
I tried to reinstall it using the .sh file from they're official website and then I found out that it was already installed so I uninstalled it from my laptop and tried to again to install it(so it would be a fresh install),but when the installer came out it told me that "All components are installed".
After that I tried cleaning my system with ubuntu tweak's janitor and tried again but yet the problem persisted, and after this I manual deleted any directories/files related to netbeans(searched the directories/files with nautilus) and yet the problem is still there.
When the installer start(without errors), it simply says:"All components are installed" and the "Next" button is deactivated.
I installed Netbeans 7.0.1 from software center but I would want to install the latest version.
sudo apt-get --purge remove netbeans[fullVersionOrSomething]and then install from your downloaded latest version.