Firefox: tools menu | add-ons | plugins | find the java plugin and click disable.
Chrome: type chrome://plugins/ into the address bar and hit enter. find java in that list and click on disable near it.
IE: (xp) start | Control panel | internet options | programs tab | manage add-ons button. find all java entries in the list and click on the disable link.
(windows 7) I don't have a vm in front of me but it should be similar to the xp instructions.
With Chrome you should block all plugins, not just Java. You will still be able to watch a YouTube video by 'right' clicking the plugin's element and choosing 'Run This Plug-in'. Steps:
Settings | Under the Hood | Content Settings... | Plug-ins -> Block All
If you selectively disable plug-ins in Chrome you won't be shown the Plug-in element and won't be able to select 'Run This Plug-in'.
Firefox: tools menu | add-ons | plugins | find the java plugin and click disable.
Chrome: type chrome://plugins/ into the address bar and hit enter. find java in that list and click on disable near it.
IE: (xp) start | Control panel | internet options | programs tab | manage add-ons button. find all java entries in the list and click on the disable link.
(windows 7) I don't have a vm in front of me but it should be similar to the xp instructions.