won't boot properly w/ ext hd plugged in

even if i disable the ext. hd in bios on option #3 & option #4, still won' t boot with them plugged in. #1 is windows boot manager, #2 is cd/dvd drive. what am i missing here?

windows loading bar twice, microsoft bar, then i unplug it then it goes to a screen to select language, cancel that then reboot

Please post back a screenshot of Disk Management - Post a Screen Capture Image
with all drives attached.

jimele said:

even if i disable the ext. hd in bios on option #3 & option #4, still won' t boot with them plugged in. #1 is windows boot manager, #2 is cd/dvd drive. what am i missing here?

What option #3 and #4?

#3&#4 are the partitions of ext. hd

It appears you have the DISK0 OS installed to UEFI BIOS on a GPT disk format as signified by the EFI System partition.

The secondary HD appears to have a normal Factory install to an MBR disk, so this would mean you'd need CSM or Legacy BIOS enabled in BIOS setup, with UEFI Boots First if it offers that setting, too. The BIOS Boot order would need to be Windows Boot Manager to boot the UEFI. To trigger the secondary HD to boot you'd need to use the BIOS Boot interrupt key at boot.

You can reinstall the secondary HD OS for a much better install than the factory install following Clean Reinstall Windows 7. I would boot the installer as a UEFI device and delete all partitions on the disk to change its format to GPT for a UEFI install. This may correct problems with the external HD blocking boot.

But I don't see the External HD in the screenshot though I specifically asked all drives be attached. Both of the drives shown appear as internal HD's. If per chance DISK1 is the external and its reading wrong, it may be because you still have all the formatting from a factory install including boot code that's obviously interfering. You'll need to move the data off to wipe it with Diskpart Clean Command then repartition in Disk Mgmt as a Data drive.

disk 1 is the external hd. what should the boot order be? is option 1,2,3,4 the order in which the computer looks for the boot command? G has program files on it, H is my backup disc. what is UEFI & GPT & CSM or Legacy? if the boot order is correct wouldn't it boot from the os drive?

The Windows Boot Manager should be the device set first to boot in BIOS Setup Boot tab. This is what boots an EFI install which you clearly have judging by the EFI System partition only issued during an EFI install. I don't think this is the problem since it boots correctly with the external detached. The problem is one we see frequently: old boot code on a drive interfering with boot from another hard drive.

If DISK1 is the External then it is being read as an internal drive. It clearly has an old install on it which should be wiped to make sure the boot code and partition table cannot still affect the EFI System boot. To do this move the data off, then carefully wipe the HD following the instructions in Diskpart Clean Command. Then repartition it as desired in Disk Mgmt. It should no longer interfere as it has no code left that can affect boot at all.

I understand this is complicated so ask back all the questions you need as we will walk you through it as we have for thousands of others without problem.

Hello All, used Ubuntu to delete files on the ext. hd, still had some files on it even after that so I used clean command, the played with volume sizes & got it split into 2 drives, so far so good. Thanks for the help!:)