reInstallation of older EX2 Ultra

I have a My Cloud EX2 Ultra that was being used at our church and the computer that was used to control it was replaced. I would like to get it operational again not sure it is compatible with the current OS 5. Is it best to start like it is a new unit or will in need to be reset to factory settings?

You need to check and see what Operating System/Firmware is on the device. If it is OS3 with Firmware 04.xx.xx then you should check this sub-forum.
Latest My Cloud OS 3 Personal & Network Attached Storage/My Cloud EX2 topics - WD Community

If its OS5 then look in the sub-forums in the community for the device.