PC won't boot with external HD

Big Chris · 22 Aug 2009 at 11:52

Got a 1TB Western Digital USB external drive the other day, it works fine once Windows (XP SP3) boots and I've copied plenty of stuff to it, but if I leave the USB cable plugged in my PC won't boot.

It posts the motherboard splash screen then just stays there. Once I unplug it and restart the PC all is well.

I've had other USB drives plugged in before and never had any trouble, the previous one was a 320GB Seagate drive which was plugged in for over 12 months without any problems.

Any ideas?

rpstewart · 22 Aug 2009 at 11:58

Is the external drive on when the PC fails to boot?

Try jumping into the BIOS with the external drive connected and check it's not doing daft things to the boot order.

Big Chris · 22 Aug 2009 at 12:05

Yeah if the drive is plugged in (no on/off switch sadly) then it halts the boot.

Good idea about the boot order, will check that now.

Big Chris · 22 Aug 2009 at 12:14

Hmmm... odd.

When the boot stops with the drive plugged in, you hear the PC post-beep twice (only beeps once without the external drive), then it halts on the mo'bo splash screen. It says "press DEL to enter setup" but doesn't respond to anything.

I rebooted and hit DEL (drive still plugged in) and you get part of the startup text, it finds the Primary and Secondary boot devices (both internal drives) then mentions "Detecting External Drives", which it finds, then goes no further.

I removed the external drive and rebooted again, went into BIOS and the boot order is as expected, no mention of external/USB drives.

rpstewart · 22 Aug 2009 at 12:39

What model of motherboard are you using?

raz0rr · 22 Aug 2009 at 21:51

I've been having the same issue with a WD 1TB just today, exactly as you described.
It's got me stumped too :confused:

miniyazz · 23 Aug 2009 at 00:34

Try enabling/disabling legacy USB support (unless you have a USB keyboard, in which case you're screwed

) that should stop it being confused/from seeing the external drive until you're in Windows. I would have thought disabling it makes more sense, but if it's currently disabled, may as well try enabling it..

Big Chris · 23 Aug 2009 at 09:58

rpstewart said:
What model of motherboard are you using?

It's an Asus A7N8X, so a few years old. Has never had trouble with external USB drives until now though.

miniyazz said:
Try enabling/disabling legacy USB support (unless you have a USB keyboard, in which case you're screwed ) that should stop it being confused/from seeing the external drive until you're in Windows. I would have thought disabling it makes more sense, but if it's currently disabled, may as well try enabling it..

Good plan, using PS/2 keyboard still so I'll give it a bash.

Big Chris · 23 Aug 2009 at 10:09

miniyazz you're a genius, worked a treat.

Still no idea why previous drives didn't cause this problem, but I'm not really bothered now I don't have to unplug the little blighter each time I turn my PC on!

miniyazz · 23 Aug 2009 at 12:43

Glad it worked, I'd been pondering it for a while then suddenly angels sang out and it was obvious

Big Chris · 23 Aug 2009 at 12:49

miniyazz said:
Glad it worked, I'd been pondering it for a while then suddenly angels sang out and it was obvious

Amen to that.

raz0rr · 23 Aug 2009 at 15:14

Bit of a hijack here, but I've got a USB keyboard (G15) and can't disable Legacy

.
Google tells me the G15 and PS/2 adapters aren't too friendly

I couldn't find an option anywhere in the BIOS to disable booting from USB, either, so that option's out the window.

My board is an Asus P5K

[EDIT] Scratch that, the G15 does work with legacy support off.

miniyazz · 23 Aug 2009 at 18:59

I'm not entirely sure what legacy support really means. It clearly isn't just all USB devices if your keyboard still works. Guess it must just mean fancier USB devices? Even a G15 will have generic keyboard function as default I suppose. But I can't think of any fancy USB stuff you might want pre-Windows :confused:

hohum · 23 Aug 2009 at 21:14

Legacy support is to allow USB devices to operate in a basic manner prior to the O/S boot process. If you turn it off you can still use a USB device in the BIOS menus or Windows etc, but not outside of that.

For example: if you try and boot off the Windows CD it will ask you to press any key to boot from CD. With legacy support disabled you will not be able to do this, as your USB keyboard isn't a supported input device at this early stage. Same goes for other stuff, such as memtest86+, DBAN, and so on.

By the way, some motherboards (my Gigabyte board as it happens) have the ability to turn off legacy storage support as a separate option. This would allow you to leave any external storage device connected during the boot process, while still having legacy USB support enabled for your input devices.