Ubuntu 11.04 PC does not see Windows 7 PC and vice versa
 

Thank you in advance. I have given the details of my installation so the exact sequence is given.
In summary, to start with, my ubuntu 11.04 desktop with Samba shares cannot see my Windows 7 PC, it can not see a Lacie NAS drive; my Windows 7 PC cannot see the ubuntu PC. File sharing is enabled.
Details --
I installed ubuntu 11.04 on a old HP Pentium 4 desktop that was running Win XP.
My intention was to get experience with this amazing free software, use Samba, and then make a NAS box with updated hardware.
I had windows xp on primary HDD that was 160 GB and I had installed Seagate 500 GB Barracuda as a Slave HDD. The 500 GB disk was fresh out the box unformatted. It was appropriately recognized by the BIOS.
Ubuntu 11.04 was on dvd and I instructed it to install to the 500 GB HDD. I accepted the ext4 as the file system and checked the format box and one single partition use whole disk.
My intent was to change boot sequences between primary HDD with XP and Slave HDD for ubuntu for me to dual boot and not mess up the whole PC.
Well after ubuntu installed itself showing all the welcome screens but when it was time to reboot after the install disk was removed ubuntu hanged up. Not only that I expected to see that my windows xp will boot up from the primary HDD but that did not happen and basically I can't get xp to boot up. No big deal as this was a practice. I ran ubuntu in recovery mode and chose to repair broken packages and after that the machine boots within 30 seconds and I am able to use all standard programs.
But the issue mentioned in summary at the top makes the experiment frustrating.
I have looked at other posted answers in various forums but I just have drawn a blank!
As I said, I have no data on the old 160 GB HDD and do not care to revive the xp installed on it. I wish to know how to use the ubuntu with samba to function as a NAS with backup.
thank you for your patience reading this.

For samba server to be seen by any other system, they need to be on the same sub-net. You have not mentioned the physical connections you are dealing with.

On Ubuntu, open a command prompt, and see if you can ping the NAS, or the Win7 machine. Any time you are dealing with servers, it is best to deal with fixed IP addresses, not DHCP as is the default on most new installs, including Windows. You will need updated hosts file on each system you want to join the windows shares. On linux, this file is in /etc/ directory, and is a simple text file called hosts. It is a list of host names to IP addresses. For example, an entry for your NAS might look like this '192.168.0.2 NAS Nas' To do a ping, then 'ping NAS' would do the trick.

IP connectivity has to work before you much with samba, and win config.

Next, post your /etc/smaba/smb.conf file. Please remove the comments, any line starting with # symbols. The outo generated ones are full of comments, and make it difficult for us to help. There are good tutorials on this board. You can fine a lot of basic help there.

W7 can be troublesome. microbucks has this thing they call 'homegroup'. That will only work with Vista and W7, not samba, or not your NAS. There are ways to get W7 to work, you have to set it up as if it were XP.

Test your IP connectivity, post your smb.conf file, and we'll go from there.

Thank you Cliff.
The ubuntu PC is connected by ethernet cable to wireless router. The wireless router is connected to the cable modem.
I could connect to the internet using firefox so I guess the machine has connectivity.
Will try to figure out IP connectivity and smb.conf file and post.
Thank you
Sam