Run in terminal following commands:

sudo apt-get install samba
sudo cp /etc/samba/smb.conf /etc/samba/smb.conf.bak
sudo nano /etc/samba/smb.conf

Add the following lines to smb.conf:

[PublicFolder]
path = /home/petrunko/PublicFolder
available = yes
read only = yes
browseable = yes
public = yes
writable = no

Don’t forget to change path.

Run in terminal following commands:

sudo restart smbd
sudo restart nmbd
testparm