Vista network permissions

I have just bought a laptop with Windows Vista, I am trying to connect
it to my LAN which is 3x PC’s all running Windows XP connected via cat 5
cable standard peer to peer and a Netgear router.

I plugged the Vista laptop into the network and it picked up the
connection, internet connection worked and I can see the other 3x PC’s
and read write data to all the XP PC’s.

My problem is:
When I go to any of the XP PC’s and try to view data on the Vista PC it
says “Access Denied No Permissions” I can see the Vista C Drive but cant
open it.

On the Vista PC I have
I have set the C Drive to Shared and a single folder to shared, set the
Permissions to Full Control on all the Groups. I have set the “Network
and Sharing Center” to:
Discovery On
File Sharing On
Public share On
Print share On
Password Share Off
Media share Off

Still the problem persists, whenever I go to any of the XP PC’s it wont
let me view the Vista PC, says No Permission.

Any help would be appreciated