This article here describes how to get SAMBA running on a Raspberry Pi.
The protocol, which is known as the Common Internet File System (CIFS) – but was originally called Server Message Block (SMB), has been implemented on other operating systems including Linux. The most popular implementation is known as Samba and it allows devices like the Raspberry Pi to act as a CIFS file server. To put it another way, it allows a Windows PC to mount a folder on a Raspberry Pi and then copy, delete, read and write files on the it.
Installing and configuring Samba on a Raspberry Pi for basic file sharing is quite simple.