I don't wish to be a pain

, but rather then shut down your hidden shares (you might need them someday), go to this link:
http://www.sophos.com/support/faqs/nimda.html. This has a disinfector and instructions on how to clean your system. Make sure that you unplug from LAN until you are sure that you are clean, and make sure that you secure your system (see instructions) from NIMDA (and CodeRed & CodeBlue) before putting yourself back into the LAN. Take a real good look at the local users and groups and kill any guest or unknown accounts that all of the sudden have admin access or have become members of the admin groups (this includes group access).
NIMDA is a PITA and you have to really make sur you have your system cleaned, secured and patched <I>(as well as anybody else that attaches to you)</i>, otherwise it just keeps showing up.
Also, just to beat the dead horse some more

, make sure you keep the ol' virus software installed and up-to-date.
Good luck!!