Install the latest version of Firefox and then the latest version of Jave
it would be worth uninstalling ALL old versions of Java on the machine. Its not generally realised that until recently installing a new version of Java did not remove older versions of the virtual machine - and rogue scripts could find and access this in the background and run "behind the scenes"
Its worth realising that at the moment theres more new malware appearing which attacks Java, Flash and the Adobe Reader than there is for Windows