If you havent solved this yet, there's a way to delete folders via CMD.
I'd say delete it, re-install it. Or take a hint and switch AV's. I'd love to use Kaspersky or Panda AV or NOD32...but im a freak for AIO suites that have AV, Firewall, Anti-Spam, Anti-Spyware, et al all in one, so im using...