Vista - Permission Woes

I really can't keep up with permissions in Vista. Permissions for other users
of the computer vs. permissions for network users when sharing files - I'm
lost. And I must've done something horrible, because somehow I've slowed
explorer down to a crawl.

Basically, it seems everything is "shared" with "all users." Whenever I try
to move or delete something from my C: drive, it asks if I'm sure (because
it's shared) and then takes a ridiculous amount of time to do. It takes about
a half-hour to delete an empty folder from the desktop - literally! Even
then, it sometimes denies me permission to delete things, even though I'm the
ONLY administrator and have turned off UAC completely.

Secondly, programs create and delete temp files and folders in the
background as always, but suddenly I'm asked permission when a temporary
folder is about to be deleted by a background process - maddening!

What did I do? Is there any way to reset permissions? I'm hoping that the
full version of Vista will give me a clean slate, but I'm afraid that the
permissions are stored in the files and simply transferring them when I get
the full version will just transfer my problem as well.

When I right-click folders and click "share," some bring up a nice little
graphical wizard to help me "change sharing permissions" or "stop sharing"
(both of which take forever and don't really work) while other folders bring
up an old NT style "permissions" dialog box - why the difference? What's
going on? AAAAAAA!!!

Thanks SO much for even reading this, much less helping me out.

Teddy