Help, Windows keeps sharing my folders...

Hi, I have a problem I can't seem to fix. I am running Windows 2000 Pro SP4. Everytime I restart and Windows boots back up all of my hard drives are shared, they don't show up shared, that is with the little hand icon under them. But when i right click and go to sharing they are all shared. I change them to "do not share" but everytime I reboot they come up shared again. Thinking it was a virus, I have run and tried over a dozen antivirus/spyware/botware/modware programs and they show nothing. Any thoughts? Any help would be appriciated, thanks.

Sean

if it says : share this folder $C or what ever $drive thats OK
thats a default for nt system
the share they mean is for user 's and or system apps
they main thing is if on net can you access these dir's
if your worried like me
go to your user groups and change the admin name to something diff
so the default admin will not be administrator and you can't be hacked so quick

Thanks, that makes me feel better, was worried for a bit there.Thanks again.

Sean