For XP home, you can't disable Simple File Sharing. Aslo, you need to boot into safe mode and login as Administrator to see the security tab.
It's all here my man:
http://support.microsoft.com/default...308421&sd=tech
If this helps I don't want your cash, though. Forums like this are all about helping people for free. If anyone took/takes your money for making a post on a free forum - they are pretty sad if you ask me.
Cache.