External USB Drives Not Recognised.

I have four external Seagate USB drives that always used to work fine. Now I find I cannot plug any one of them into my win10 machine and have them be recognised. In fact the last one I tried froze the boot up. I had to switch it off to get out of the lockup.

Other times it hasn't been that bad - it has booted with one attached but I've not seen any sign of it in win explorer.

The USB ports I've used are working fine judging by the fact that I can plug a 32G USB stick in and operate it fine.

I recently tried to install a PCIE 1 USB card and that never worked either. Maybe that screwed everything? I don't know.

But now the machine has that card out again and I have four USB ports that work with a thumbdrive but not with my Seagate external drives.

winver 22H2


Could it be that all four external drives are sick? How can I best troubleshoot this prob ?

If you are in the habit of plugging/unplugging multiple external USB drives then you may have run into a longstanding Windows bug... a surfeit of USB device enumerations where the number of entries in the Windows registry overwhelms the OS' ability to recognise further USB connections.

Have a look at this earlier TenForums post.

Use USBDeview to clear extraneous registry entries, reboot and try again.

Hope this helps...

RickC said:

If you are in the habit of plugging/unplugging multiple external USB drives then you may have run into a longstanding Windows bug... a surfeit of USB device enumerations where the number of entries in the Windows registry overwhelms the OS' ability to recognise further USB connections.

Have a look at this earlier TenForums post.

Use USBDeview to clear extraneous registry entries, reboot and try again.

Hope this helps...

Good idea and interesting. I had 221 entries. Cleared them out. Unfortunately doesn't seem to have fixed it. Perhaps I should not have hoped it would given that thumb drives are recognised? I will check my USB drives on another machine today when I can get to one. Seems a bit wild but I suppose all four of them could be damaged - perhaps all got the same virus or something?
It would help with this investigation if I could hot swap them. Should we be able to hot swap external usb hard drives?
I know the web says we can and I have done so in the past but perhaps rigorous correct protocol is otherwise?
Right now I'm not doing it in an attempt to minimise possible sources of problems. But how tedious.....
Plus I got frightened off the last time I did try hot swapping. When I plugged one of these Seagates in I got beep, beep, beep continually and it never showed up on Explorer.

dalchina said:

No reply so no comment..

Maybe you are referring to your post where you queried if there was anything in common etc. ? I was waiting until I got an opportunity to try the drives on another machine.

I've now done that. I got access to a windows notebook and a linux mint box. The drives are seen by both and accessible no trouble.

Anything in common? Not really. I have four USB ports on this machine coming in pairs from two motherboard sockets. I randomly try any of the four and get the same results.

Bit of a funny one. I don't know. Difference in power requirements seems the best to me right now.

The box has a 450W PSU and is currently driving only two hard drives. C: and I: , two SATA connected inbox drives.

The system assigns D: to the thumbdrive I've been saying I can plug in anywhere and it works fine - indicating to me the ports are okay.

Why the system ignores drive letters E, F, G, H I don't know. Relevant?

dalchina said:

Thanks.

What happens if you plug in 2 flash drives? Is the second allocated E?

When you plug in one of your USB hard drives, is there any indication power is reaching it? (light, whirring...?)

I just tried. It allocated E: and it reads okay.

However the 'quick access' part of the win explorer pane shows E: with a query but down in 'this pc' part of the pane it shows it as normal. if that has any significance.

yes the hard drive gets power. there are no leds but I feel it vibrating.

abrogard said:

Good idea and interesting. I had 221 entries. Cleared them out. Unfortunately doesn't seem to have fixed it. Perhaps I should not have hoped it would given that thumb drives are recognised? I will check my USB drives on another machine today when I can get to one. Seems a bit wild but I suppose all four of them could be damaged - perhaps all got the same virus or something?
It would help with this investigation if I could hot swap them. Should we be able to hot swap external usb hard drives?

It was a thought... but 221 entries is nothing, IME.

The success (or not) of hot-swapping USB devices is down to Windows' behaviour towards them... and whether you choose to amend Windows' default behaviour, as I'm sure you are aware.

RickC said:

It was a thought... but 221 entries is nothing, IME.

The success (or not) of hot-swapping USB devices is down to Windows' behaviour towards them... and whether you choose to amend Windows' default behaviour, as I'm sure you are aware.

No I don't know much about windows behaviour in regard to hot swapping. We can influence it? I didn't know. Perhaps I should know more about that? But the hot swapping of the USB sticks doesn't appear to do any harm at all.

abrogard said:

But the hot swapping of the USB sticks doesn't appear to do any harm at all.

The default Windows OS behaviour is 'do no harm'... but it's togglable so - yes - you can 'influence' it.

I suggest you read around the subject before making any decisions.

Hope this helps...