Pasworded file sharing

[Pickers]

ok I have a desktop PC and a laptop. Neither of them uses profiles. I have a folder on my laptop which I have enabled sharing for, and allowed "other users on the network" to change the files. This is so I can change them from the desktop PC.
However, Its quite important files in their, and so i wondered if there was a simple way for windows to bring up one of the username/password profile prompts when you try and open this laptop folder (mapped network drive) from the desktop PC, to offer at least some security. Its a folder I can't move into "my documents" and so making the folder "private" is impossible right? Any advice from anyone?

 

[Skilldibop]

you can make any folder private, but it'll remove any file sharing on it.
Do the user accounts have passwords on these PCs? If so just set permissions that only user x can access it (x being local) then map the drive as a different user name.

 

[Pickers]

no they dont. I'm using xphome, so I dont think there is a simple way around this.. I'll just manually share/unshare the file when I need it