View Full Version : Win7 & USB issue

27-04-2017, 03:42 PM
The old Win7 PC is having issues with 1TB & 2TB USB drives

It detects them
the drives show in DiskManager,
but it cant see the NTFS partition , not in explorer or disk manager

USB memory sticks : no issues

The 1Tb USB Drive works just fine on other PC's, even XP can read the partition .
Any ideas , anyone seen this before ?

27-04-2017, 03:49 PM
One possibility, I had a 500GB that needed a second port for power or it would act the way you describe. Some machines gave it enough power from one port and others didn't, it came with a cable that had 2 plugs for this reason.

27-04-2017, 03:57 PM
Open Disk manager, make sure the USB drives have been allocated a Drive letter.

Got a XP that does similar, for some reason it wont give USB external drives a letter, manually giving it then they POP up and appear.

27-04-2017, 04:16 PM
The PC sees it as unformated , so cant add drive letter. Im not going to format it as it has data on it (readable on other PC's)
The 2TB is externally powered .

Very strange, didnt have any issues with smaller 500G USB drives in the past , but may be red heering
Unfortunately, would be quicker to wipe & reload the PC ,than hunt the interwebs & try all the fixes that often dont work :annoyed:
Pitty , as otherwise its a reliable PC. (its the workshop PC)

27-04-2017, 06:48 PM
Tried removing all the USB bits in device manager and restarting?
If your keyboard and/or mouse are USB though this can be tricky. :)

27-04-2017, 07:47 PM
Have you tried: Right click 'Computer' on desktop/Left Click 'Manage'/Left Click 'Disk Management' (wait for 10 seconds or so), Under/In the 'Volume Column' Right Click the offending drive/ Select Change Drive Letters and Paths/Name it.

This is an historic issue in especially Win 7, it has been addressed on this forum a number of times before.

I seem to remember it happening with Portable USB HDD's, don't think the problem is caused by the size of the disks.

28-04-2017, 12:28 AM
Show a screenshot of the drive in disk management and it may explain it more.

Also, show a screenshot of it working in another computer.

If not, its probably the partition table. Windows fix has always been to format when it can't read anything, floppies were notorious for that.

Fixing a partition table should not destroy your data, but back it up. MBR is not as reliable as GPT.

28-04-2017, 10:38 AM
there is NOTHING wrong with the drives or partition tables . They work perfectly & 100% readable in other PC's
On the PC in question , Diskmanager shows the drive as blank , no partitions .

"Have you tried: Right click 'Computer' on desktop/Left Click 'Manage'/Left Click 'Disk Management' (wait for 10 seconds or so), Under/In the 'Volume Column' Right Click the offending drive/ Select Change Drive Letters and Paths/Name it."
That doesnt work, as Win doesnt see any formated partition to assign a drive to.

A reload (or retirement of the PC) might be the quickest way.

28-04-2017, 12:21 PM
Depending on home much you want to bang your head trying to repair it ;) :badpc:

Have you tried running chkdsk Just in case it will fix the problem ?

Otherwise, if your feeling game, theres a possible solution on windows-7-notices-but-does-not-see-external-usb-hard-drive (https://social.technet.microsoft.com/Forums/windows/en-US/dd9cd509-f9ac-4295-a75b-863f92f5595f/windows-7-notices-but-does-not-see-external-usb-hard-drive?forum=w7itprohardware) Scroll down the page till you get to the post BELOW "Zeallot" The post starts off with------
I had the same issue and it turns out my windows 7 install somehow didn't include 1 INF file that allows usb mass storage devices to work: usbstor.inf The guy has posted a LONG list of commands that can be made into a .inf file, create it and it rebuilds the USB .inf (I suspect a reboot may be in order first)

Worth a crack, otherwise sometimes its just as easy and faster to reinstall. OR even try a repair install :2cents:

29-04-2017, 04:25 AM
Can you do a sfc /scannow check?
if no problems are found, try to put the drive into another pc and run a chkdisk then return it back to the pc and try it again.

Also is anything popping u in event viewer when the HD gets plugged?