First log in to your web admin and go to the devices tree - find the PC that is acting as the file server and expand that node to see the share(s) underneath. Click on each share and look at the properties in the right pane. Down the bottom there is an online tick box. Is this ticked on?
If yes:
Go to the media file sync menu of the web admin, and navigate down to your media (eg /home/public/data/etc... in the left pane). When you see your media files, they should have a big tick icon next to each of them, not a drive icon. This confirms they have been scanned into your media database. Note the scanning process can take a long time (many hours) if you have a lot of data. And depending on your folder structure, may not start appearing in the UI until towards the end. If you only see drive icons, even for media files in the top/first folders, then perhaps your UpdateMedia daemon isn't running for some reason. You can try manually hitting the button to resync your media in that window - it will open a log window and you can read what it is doing. The sync into the SQL database should be in the last few lines, so read towards the end of the log as well.
If no:
First try ticking it and clicking Save. Wait for at least 10 seconds, then refresh the screen and check whether it is still ticked. If yes - then UpdateMedia should start running soon and picking up your media. If no - then you may have the cifs/smb protocol issue. In the share properties further up you will see a field that says something like filesystem type:cifs change this to smbfs and click save. Now monitor that tick box again.
If the tick box keeps unticking, then you need to look for a genuine networking issue. I always recommend getting a known good patch cable and connecting directly from the core to the PC as a first step to eliminate your switching and cabling infrastructure as a cause. Also, looking at your NIC for known compatibility and drivers... etc
