VISTA,,,,With UAC on vista it seems a little over the top for secirity, but right click that file you cant delete and just try once more, if not then make sure you are the admin of that vista machine.
XP,,,,Delete all Java and update click here . For macromedia remove old and install fresh click here .
I had this happen to me a few weeks ago and what i explained here seemd to have fied it for me.
Best of luck.........