Win 10 won't boot with an external drive attached

[Reverend]

Win 10 won't boot with an external drive attached and if this isn't fixable it's going to be super annoying because I'm often working with 3 or even 4 drives plugged in.

Thanks - rev

[Midknyte]

Did you check your boot order in the BIOS? Make sure the internal drives have higher priority than USB.

[Reverend]

Good point, I don't think I did that. Thanks.

[Reverend]

I checked, the only boot drive in the boot order is my M2 SSD. None of the drives that are preventing win 10 from rebooting have any windows.iso's or boot disks on them.

[Midknyte]

None of the drives that are preventing win 10 from rebooting have any windows.iso's or boot disks on them.

That doesn't matter. It will still try to look at the USB drives first if they are connected.

Where did you look at the boot order? It should list the order of devices/ports to boot from like USB, CD/DVD, Network, etc.

On pg. 22 of the manual, it mentions CSM. If that's enabled, then you'd see options to boot from Network Devices or Storage Devices.

[Reverend]

>Where did you look at the boot order?
In the boot order section. CSM is not there, I'm in UEFI mode, there is no failover entry.

>It should list the order of devices/ports to boot from like USB, CD/DVD, Network, etc.
Normally. In this BIOS you don't see a bootable possibility until there's more than one. i.e. it's currently set to M2, if I now insert a flash stick with an OS on it, it will show me both possibilities, the second as a failover or second boot device. Remove that stick and only the M2 will remain.

[Midknyte]

Most BIOSes (UEFIs) have a section that lists Hard Drives, Optical (CD/DVD), USB, Network, etc. You might have to poke around the advanced settings to find it.

On pg23, it mentions Boot Option Priorities. Did you check that?

[Reverend]

>It sounds like it's showing "bootable" devices, not the actual boot order detection.
Yes, that's exactly what it seems to be doing.

Yeah, I checked the options but as above, it only seems to give me options when they're physically there.

BTW: The problem went away. One of the drives I thought was hanging it up was a 4TB drive with a lot of stuff on it. Maybe I didn't wait long enough. The other drive may well have been my boot iso. Whatever the reason, the problem has gone.