Limiting a shared folder

[Dist]

I want to be able to share folders on my vista machine and laptop, but limit it so other network computers cant view the shared folders. Ive tried playing with permissions, but i cant seem to be able to set permissions for users on other computers on the LAN.

The add permissions window has the location Dist-vista64 (computer name), but when i try to change it, no other computers show up, just like on my laptop it only shows Dist-laptop and doesnt show my PC.

 

[Dist]

Both my laptop and pc use the same username and pass, the problem is, even with my pc set up so that "people must have a user account and password on this computer to access shared folders" other computers on the network, ones with compleatly different usernames/passwords can still access the folder without a password.

Only recently have i got my laptop and already im running into annoying problems, like due to me using vista home premium, and not buisness or ultimate, i cant use my laptop to remotely connect to my pc, and now i cant share the folders the way i want too, just because i dont haev active directory.