Symmantec Live Update not working with Vista

my university offers Symmantec antivirus free to all students... it was working great on my Vista system but after jan 10 vista updates my liveupdate ceases to update or function anymore. i had a trojan that symmantec caught but after that it finds nothing and my computer is acting odd. it always prompts me to use live update then never opens it...

any solutions?

i have windows defender in the mean time working to help but im on unsecured networks for the college wireless and not having up-to-date virus definitions is starting to worry me.

someone help.