If you use Malwarebytes Antimalware turn it off. Deactivating its functions doesn't help. You need it to quit it completely. You will gain 12x to 20x build speed increase. It doesn't affect speed of netbeans startup but it drastically speeds up netbeans cleaning iand building. I also reccomend quiting netbeans and deleting entrie cache folder (in windows inside: C:\Users\<user>\AppData\Local\NetBeans). Restart windows. Projects will scan for looong time. Don't quit netbeans, do not write any code or reconfigure your projects. Just wait till scan finishes. Restart netbeans. Scanning should be faster now. Remember, do not run malwarebytes antimalware when you use netbeans. Make sure Antimalware icon is not on your tray.