ReadyNAS 102 - WebDav windows 10 issue

Basically I'm trying to setup WebDav which i have done opened the ports for the router etc.

when i have the permission "Everyone" set i can map a network drive offsite to this NAS no problems but as soon as i remove the permission "Everyone" it just keeps asking for the u/n & p/w.

i set the file share to admin and tried creating new user account but i just can't seem to connect via a mapped network drive, i have allowed it through the network and security and ran the webclient service on the PC yet nothing.

i can access it through a web browser fine.

Any help would be great

Thanks

David