|First of all WD hard drives have a third jumper setting for Master alone, which is used if there are no other drives connected to the same cable as the WD.|
You do NOT need to configure the two drives for a dual boot if all you want to do is use one of the drives for storage or to access files on it. You only need to have both boot if you nedd to run programs installed on both.
If one or both of the drives came out of other computers it is unlikely the drive will boot without a Windows repair or re-install.
If one of the drives is currently booting and running in that computer the only thing you may need to do is to reset the boot order after introducing the second drive.
Windows will assume you want to boot to the latest drive so you will need to set the boot order back to original settings. If that doesn't seem to work for you then make sure the boot drive is the Master on the Primary IDE channel.