Because of WCry 2.0, people turned off SMBv1 protocol. So, to mount that Windows Share folder, we need to adjust by defining the protocol version. Thus, mounting:
sudo mount -t cifs //[WINDOWS_IP]/[WINDOWS_FOLDER] /mnt -o username=guest,uid=1000,vers=2.1
sudo mount -t cifs //192.168.1.2/jav /mnt -o username=guest,uid=1000,vers=2.1
Change uid with your own UID. We could use protocol 3. But, in this example, I used SMB version 2.1.