For those of you who are running Windows 8.1 or 8 (or possibly 7, but I didn't check) and get an error trying to map a network drive to your Synology NAS, you may need to turn on the following Windows Feature - SMB 1.0/CIFS File Sharing Support.

You access this through the Control Panel -> Programs -> Turn Windows Features On/Off. Scroll down in the list and make sure that SMB 1.0/CIFS File Sharing Support is selected. I think this is typically enabled by default, but I must have turned it off at one point.
After enabling this, I was able to map a drive and use the Disk Replicator program. Before that, I was getting an Error Code 64 (Authentication Failed) when attempting to map a drive through the Synology Assistant or login through Disk Replicator. Map Network Drive in Windows Explorer would just give a "Windows cannot access" Network Error.




