@MasterG
Thank you for your comments; in response, some clarification:
Re U to U - understand; however it is usual in my experience for the manufacturer to follow these sorts of issues, so hence request for interest....
Device works fine when connected with USB cable. When attempting to use eSATA, is recognised at Device Manager level as a disc drive, but fails to mount under normal use. However, have found that is connected prior to PC boot, it will then mount and has been possible to transfer data but is unreliable - tends to cause PC freeze after indeterminate time.
Re BIOS - yes have checked BIOS is latest edition. Also that eSATA is defiitely Enabled in the BIOS.
Any additional ideas will be most welcome
Regards,
Kevin