I use a USB stick (64gb) which was previously working.

Today I plugged my USB into my computer and it said "you need to format the disc in drive F before you can use it" so I click "format disc" and it says "windows was unable to complete the format".

When I check in disk management, it says the capacity is 8mb (was previously 64gb) and the file system is RAW with no partitions.

I have followed a few tutorials I found online but none have helped.if if I'm not worried about losing the files on the USB as they are backed up. Also, when I go through cmd on windows to format the disk it says "virtual disk service error - the cluster size is too big"

Someone suggested using a MAC to fix it but I don't own one. Tried the disk defragmenter, the disk does not appear in the list of disks able to be defragmented.

I have only used 4GB of space on this disk since I got it 2 months ago.

  • 1
    When you say it was working before, do you mean you were able to use the whole 64GB; that is, was it ever (nearly) full? Or had you never used up too much of the space yet and added some more files just before it failed? – Synetech Oct 15 '13 at 2:37
  • I'm really baffled -- this is exactly the same post shown here answers.yahoo.com/question/index?qid=20130327195746AAjug8A or uk.answers.yahoo.com/question/index?qid=20130327195746AAjug8A -- and yet that one was from 7 months ago. ?! I don't get it! – Debra Oct 15 '13 at 3:11
  • Nice catch @Debra. I’d have guessed that it happened to him again and he just copied their previous post, but he’s using a different name (cody, not Aaron). My next guess would’ve been that there is some kind of person or bot that is creating accounts and copying questions from other locations, but cody seems to have followed up (he edited the question). At this point, it seems likely that cody had a problem with his drive, did some research, found one of the other posts, gave up, and asked here and for some reason copied the other post instead of writing it themselves (maybe he’s foreign?). – Synetech Oct 15 '13 at 4:11
  • I ONLY USE 4GB WORTH OF SPACE I GOT THIS USB 2 MONTHS AGO It’s a cheap drive you got on eBay or something instead of a brand-name one from a store right? Unfortunately this is common with cheap flash-drives and memory-cards from eBay, etc.; they tend to be fake/counterfeit. They’ll advertise them as being large, but in reality, they’re very tiny. They are hacked to look like they are big, and will only work until you try to put more data on them than they have actual space for (sometimes not at all). You might be able edit them to limit to their true size (yours seems to be only 4GB). ◔̯◔ – Synetech Oct 15 '13 at 4:23
  • @Cody : "virtual disk service error - the cluster size is too big" clearly points to what Synetech stated above. The disk is fake.what ever it is. Try gparted. – Renju Chandran chingath Oct 15 '13 at 5:14

This problem, usually happens when the file system gets all tangled up.

Format your USB drive using HP USB Disk Storage Format Tool.

It totally clears out everything and put up a new and fresh file system so that you will be good to go.


After trying the following suggested fixes

  • HP USB Disk Storage Format Tool (couldn't format - write protection)
  • Diskpart (couldn't create partition)
  • Remove Regedit write protection (didn't change anything)
  • Many other tools (nothing changed with these too)

I came across this post which fixed my 2 corrupted usb sticks have trying to run the Microsoft MediaCreationTool : http://html5.litten.com/updated-how-to-fix-external-disk-drive-suddenly-became-raw/ It uses TestDisk (http://www.cgsecurity.org/wiki/TestDisk_Download) to change from RAW back to NTFS the usb sticks.

  • 1
    I'd recommend summarizing the linked blog post in your answer, because it would not be very useful if the link is taken down. – bwDraco May 27 '17 at 1:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.