Problem with administrative right on vista

I have windows vista home basic on a dell 1525 laptop.
I have only one user on my system that is also the administrator. I have confirmed this via control panel > user accounts where below my user name "Administrator" is displayed. But in spite I being the administrator there are three problems that I am facing (there could be other problems as well that I have not yet discovered). Here are the problems listed.

1. I am not able to share file/folder on my system. When I try to share a folder it says "file or folder could not be shared" but at the same time the icon of the file/folder changes indicating that the file/folder is shared but in the property it is still showing that the file/folder is not shared.

2. When I connect to another computer using LAN connection I can see the other computer connected to me but I am not able to access its shared file/folder. when I try to do it, it says "You do not have permission to access. Contact your administrator". Although the other computer connected to me is able to access my shared file/folder (ya I know the properties of the shared file/folder on my computer shows that it is still not shared. Refer point above). I don't know what is the problem

3. When I create a wireless network and try to share the Internet trough my computer, I am not able to do so. But at the same time if some one else does it I am still able to access Internet through them.

All these three problem looks like they are not connected but somehow I feel it is all because of the administrative right problem on my system. Can some help me the matter. I hope I have explained problem well.

 

Vista - NEW OS

Reload it and start again