Originally Posted by pbarach
Ok, so as I thought, SMB requires an external hard drive, and I continue to need DLNA to serve audio files from my PC.
No, not at all. You can use the built in Windows sharing functionality to share any drive / folder on any drive on your PC (whether it's an internal or external drive doesn't matter) to get the SMB shares you're looking for. In Windows Explorer:
1) Right click on the folder you want to share and select Properties.
2) Go to the Sharing tab and click either the Share... or Advanced Sharing... button to configure the share name and who can access the share.
3) Once done with the Sharing features, go back to Properties and go to the Security tab.
4) In the Security tab, make sure the username you're going to use to connect to the share is given at least "List folder contents" and "Read" access to the folder. Note that there's a special user called "Everyone" that you can give access to, which won't require you to provide a username and password when connecting via the Oppo player.
If you did everything correctly, you should now have a SMB share you can access from the Oppo.
Keep in mind that it can sometimes be a PITA to get the shares configured properly so you can actually access them, but you don't need to purchase any additional hardware or software to use SMB shares in Windows.
Also keep in mind that using SMB shares doesn't necessarily give you anything you can't do with DLNA, which tends to be a LOT easier to get working. But since you're running into issues with some files not showing up, it's probably worth a try.