Medion NAS - how to log in on private folder

[kurm28]

Hello All

First - hello everybody. It is my first email on this forum.

Second - I need your assistance regarding the way I may login from my Windows 7 on NAS placed folder, set up as a Private with specific person as an owner.

To be more precise:
I have an MEDION NAS - 1TB (don't remember the symbol).
I have few folders made on the NAS HD and I would like to secure one, and set up a limited access to it.
I prepared an user - RAF - and made the folder as RAF user propriety, secured with the password.
Now - after NAS reboot, I'm not able to get in this folder from my Windows computer, without the password what is normal.
Windows is asking for the user and password.
The question is how to link the RAF user name with the Windows window where I'm asked for the access password, or which user name prepare on NAS system, to let Windows get in the folder?
When I put in Windows7 window RAF as a user and give the password - it not works.
When I made a user same as the Windows computer name - it not work.

Please advise how to set up all this to succeed.

Thnx in advance

kr
Raf