But this is never simple.
Did you put the second drive on an SATA connector higher in number than the boot drive?
Hello there.
Some years ago(around 4-5) i bought a 500gb Western Digital external hard disk drive, i was working on my PC on some data through the external disk and it suddenly died,i restarted the PC and since then it couldnt be read,i contacted WD but they said they cannot help me. My thought was to open the plastic box covering the Hd and use it as an internal device so i connected both SATA and power supply cables. Then i restarted my PC and after the memory check, windows check for the hard disks too, then it could find both my disks,the first one where i store the OS and some data, as well as the external HDD. But the problem is that just after the WD drive is detected windows just freeze,i cannot do anything and my PC won't keep working. If i press the reset button,when the system reaches the same process,it just wont read the 2nd plugged disk,it detects my 1st disk,pauses for a while(around a minute) and then keeps running without even recognising the 2nd one. So what i do in order to keep my PC running is to just unplug the 2nd one and restart my pc.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic