There are a couple of issues that could lead to this:

1. Enabling Netbios in your samba configuration file

   
   
   

   in your /etc/samba/smb.conf file, after the WORKGROUP line, add the following:
   
   netbios name = PC_NAME Where PC_NAME is the name of your PC as it will show in the network. Then reset the samba service sudo service smbd restart




2. Not having STATIC IP

   
   
   

   Need to have static IP set in order for other PCs on that network to see you. This also depends on your router and the configuration of your network.




3. Hostname length should be less than 15 characters

   
   
   

   If your hostname is longer than 15 characters it will give an error in some cases. Type hostname to see your hostname. To change it you can either:

   
   
   

   sudo sysctl kernel.hostname=NAME

   
   
   

   or you can edit the /etc/hostname file and reboot.




4. In the /etc/samba/smb.conf file, look for the line that says the following:

   
   
   

   # What naming service and in what order should we use to resolve host names
   
   # to IP addresses
   
   ;   name resolve order = lmhosts host wins bcast
   
   

   
   
   

   Uncomment the line that says name resolve order and make sure that bcast is the first on in the list, should look like this afterwards:

   
   
   

   name resolve order = bcast lmhosts host wins

   
   
   

   Then restart the Samba service as I mentioned above.

This is all assuming it is Ubuntu the problem, you have already Samba installed and you are not working through Active Directory.

In many case it is also Windows. You would need to do stuff like flush the DNS and the register to it. On Windows in the terminal (cmd) do the following:

ipconfig /flushdns

ipconfig /registerdns

You need to reboot the PC afterwards. After this, check to see if you can see the Ubuntu PC by doing for example net view in Windows.