Stuck on start up when 6TB disk connected

[FisherBoy]

So, I wanted to upgrade my HP Pro 3500 Series with larger disks (4TB and 6TB).  I can successfully boot off a WIndows 10 SSD, or an OpenElec USB, with only the 4TB Western Digital disk connected.  if I connect the 6TB WD Red disk, then the boot process gets stuck on the BIOS loading screen (at the point where you would usually press the appropriate key to enter BIOS settings).  BTW, pressing the key to enter the BIOS at this point doesn't do any thing at all either, as the system doesn't respond.

I can confirm that the 6TB disk is fine, as it works in any other PC I've tested in.

How can I fix this, if it's at all possible?

[TheOldMan]

I suspect it is due to the 6TB drive and its setup.  I also tend to believe this statement "I can confirm that the 6TB disk is fine, as it works in any other PC I've tested in." is not entirely correct.  Many PC's cannot tolerate a 6TB drive.  Most drives bigger than 2TB need to be "prepared" since they either require a GPT formatting or special preparation before they can be used.

Since the largest drive available from HP at the time of production was 2TB, I suspect the drive needs some special help to work in this PC environment.

[FisherBoy]

Thanks TheOldMan for your feedback. 

The 6TB disk is working in an even older Dell Optiplex GX620, along with the 4TB disk.  And as I mentioned, the 4TB disk works just fine in the HP, without my having done anything.  

I'll try backing up the data and reformating the 6TB.  Not something I want to do, given the amount of data.

[TheOldMan]

That does seem to be odd behavior.  When this boot failure happens, are you trying to boot from the 6TB drive or just using it as a data drive?

I would suggest checking in the BIOS to see if the boot order is getting changed with the presence of the 6TB drive, also.