Can I disable Auto Update (for example, while running tests)?
The IDE often checks for updates on startup. This behavior may not be desired in some cases; for example, when running tests on the GUI, because they can slow the application down or potentially change its behavior from what you expected. In order to prevent the Auto Update check, run the application with the netbeans.full.hack system property set to true. For example, use -J-Dnetbeans.full.hack=true on the command line.
Setting this property has some other side-effects; see: DevFaqNetBeansFullHack
Functional tests using NbModuleSuite get this property set automatically. So do unit tests using NbTestCase (though they would rarely need it anyway).
Applies to: NetBeans 6.5 and later