uninstall java completely, see here: http://www.java.com/en/download/uninstall.jsp
or use revo uninstaller. get it here: http://www.revouninstaller.com.....nload.html
find it in the list of installed programs, select it, and hit uninstall.
clear out your temp internet files, cookies, & cache.
see here: http://www.wikihow.com/Clear-Y.....Explorer_8
or, as i would, use ccleaner. get it here: http://www.filehippo.com/download_ccleaner/
at this point, personally i'd shutdown and restart the comp.. then ...
reinstall java, see here: http://www.java.com/en/download/windows_xpi.jsp
once installed double check a few of these settings ...
hopefully this helps. theres some other settings under the advanced tab that you can double check as well but im not too sure which to tell you to enable. will try and have a look around to see if i find a good guide.