Windows 7 cant see 2 identical external usb drives

120_Minutes

Problem: I have 2 identical 500gb iomega external usb HD's. one is brand new and empty. i want to transfer all my media from one drive to the other. however when both drives are plugged in and on, windows 7 will see one but not both. its happening with both my machines (desktop and laptop) all my usb ports are 2.0 and not powered from a hub (desktop is a pci card)

i dont have enough HD space on either of my machines to dump all my media there as a temp measure, so i really need W7 to see both drives.

help!

Overheal

it can see either drive or just one particular drive? youve tried all possible USB connections?

Capt'n Midnight

right click on one of the drivers and rename it


you may also be drawing too much power , yes it's up to 500mA per port but it doesn't mean the mother board can supply 500mA to all the ports all the time

try using ports as far apart on the machine as you can

when you eject the drives, tick the box to show all the letters and stuff in case you've missed



only if all else fails go in to disk management and assign a drive letter

Gurgle

120_Minutes wrote: »

Problem: I have 2 identical 500gb iomega external usb HD's. one is brand new and empty.

Have you partitioned and formatted the new empty one?
If not it won't show up under 'My Computer'.

120_Minutes

Gurgle wrote: »

Have you partitioned and formatted the new empty one?
If not it won't show up under 'My Computer'.

I didnt, but if i just plug in the new drive it sees it fine. if i just plug in the old one it sees it fine. if i plug in both it sees whatever one was plugged in first.

the old drive is renamed.

i have trie every combination of usb ports on both machines (laptop has one on rear, one on left, and two on right) desktop has 3 on pci card.

both drives have their own power supply.

i really cant figure it out...

Overheal

This is an odd problem that shouldnt be arising yet but iirc 32 bit OSs cant see more than 4 Terabytes of Storage. If youre over that limit that could be the issue. Or maybe that was 4tb per partition. nvm.

kierank01

So you have 2 W7 machines, the easiest way that I can see for this, would be to plug 1 hd into each of the machines. and transfer the data over the network.

I know that it would be very slow, but I don't see another way around it.

TeaServer

Capt'n Midnight wrote: »

......
only if all else fails go in to disk management and assign a drive letter

^^^^^ What he said

When you plug in the drives on their own, do they use the same drive letter? If so one of them wont show up when they are both plugged in at the same time.

Use disk management tool to change the letter for one of them. I had a similiar issue at work once, when a new network drive was using the same letter as an external drive I was using.

Alternatively (I apologise in advance for using the L word in here), use a Linux boot CD and both should be mounted automatically on the desktop for you to copy your data between them without any drive letter issues.

/T

120_Minutes

ok, so i ran disk management and have the following screengrab.

C is of course my OS, which is on an internal 120gb IDE
D/E is a single 120gb IDE internal partitioned for files.
I is the current USB external.
the offline drive below I is what appears when i switch on the new drive, the curious thing is: i powered on the current drive to check its letter (I) then powered it down. I then powered up the new drive to assign it its own letter (J) and then also powered it down. powering up the old drive again and windows is now calling it J!

so i went back and renamed the old drive I, left it powered on and then powered on the new one, which is when i took the grab.

so how do i solve this "signature collision"?

Gurgle

Did you click 'Help'?

120_Minutes

Gurgle wrote: »

Did you click 'Help'?

Ashamedly no, as i've found windows "help" to be less than helpful in the past. but perhaps 7 is different. i'll give it a go when i get home from work.

Gurgle

120_Minutes wrote: »

Ashamedly no, as i've found windows "help" to be less than helpful in the past. but perhaps 7 is different. i'll give it a go when i get home from work.

Unfortunately its no better.
I think it happened to me once that there was actually something helpful in the 'problem fixer wizard'.

sandleman1979

Does this help..??

http://blogs.chron.com/techblog/archives/2009/09/signatures_in_collision_bringing_back_a_120gb.html

Overheal

At that point you need to contact Iomega. There may be a firmware change you need or some other method they have for this fix.

120_Minutes

sandleman1979 wrote: »

Does this help..??

http://blogs.chron.com/techblog/archives/2009/09/signatures_in_collision_bringing_back_a_120gb.html

yep! i never thought of right clicking on "offline" in disk management, as it didnt look like a link.

done!

thanks guys!