Can file manager be setup in a such a way that replication only happens in one direction.

From server -> driveHq -> remote workstation.

If a change is made on the remote workstation, that it is not replicated back to the source.

The current version doesn't support it. We are working on version 4.0, which will support it; Version 4.0 will also support scheduling sync tasks.

My File Manager doesn't connect from my pc . What should I do to connect it easily and upload my files.

Please check whether any antivirus or security software is blocking drivehq.com.  please also try connecting from internet explorer first.  Please email support@drivehq.com for further assistance.