Merge Partitions On USB Pen Drive To Use The Unallocated Space


Few days back, I made my 4 GB USB pen drive bootable with a developer version of Chrome OS. To make my USB pen drive bootable, I used a tool which creates Linux based EXT partitions on the USB drive. All worked well and the bootable pen drive worked well.


After few days when I wanted to transfer some data I formatted the 4GB pen drive in Windows and I was surprised to see that Its showing only 941 MB of drive space. I formatted it again and it was still only 941 MB drive.


I opened Disk Management in windows to analyze the disk and came to know that the tool which i used to make my USB pen drive bootable, had partitioned my Pen drive into two parts. One of them was 941 MB of FAT partition which was usable and the remaining 2.7GB was showing as unallocated space.


In this article I will tell you how I recovered that space by using another tool.


The unallocated space shown in the disk management console of windows was actually Linux EXT partition which is not readable by Windows. As I no longer needed that USB drive as bootable, and wanted to recover the 2.7 GB space allocated to Linux partition, I tried to do a low level formatting of the USB pen drive using some freeware tools. It did not help to recover that Linux partition.

Also the problem with Windows is that It won’t let you create or Merge partitions on a USB pen drive using the Disk Management tool.


I came across this tool called BootIt by Lexar. What is does is that it allows you to set the removable Bit of the drive which will trick Windows into believing that the drive is not a removable drive.


IMPORTANT NOTE: Before following the below method Make sure to backup all your data on pen drive. This process will result in erasing all the data on pen drive.

If you are using Windows Vista or Windows 7, just run the tool with right click and choosing Run As Administrator option.


Now simply select the drive on the tool below and click the Flip Removable Bit button. After you press it, the tool will ask you to remove and re-insert the drive. After you re-insert the drive into the USB port, it will be non-formatted all RAW space.

Windows will prompt you to format the drive, just go ahead and format the USB drive and it will reclaim the unallocated space just like i got mine back πŸ™‚


Hope you find the tutorial easy to follow.

Download BootIt Tool By Lexar


  1. Good article !

    But why can’t we use any partition tool that can also read a linux partition ?

  2. I Have the exact same problem with your,the chrome OS and stuff,though when i tried to write the image to my disk,it got corrupted.Everything else afterwards is the same as yours but when I tried the corrective procedure it does not work.Thing is it windows doesn’t ask for formatting after flipping in BootIt.Thanks and please help.

  3. @Eric
    You have to remove the drive and insert it again after the flipping. I hope you have done that. And to be sure that the drive is not damaged, right click on my computer icon, click manage, then open disk management. Observe the status of the disk there when its connected.
    hope it helps. Please comment back after trying this.

  4. Excellent, I’ve been searching the web for an hour now after installing the new chromium flow os on my usb stick. This is the only post I could find that actually fixed the issue.

    Thumbs up!

  5. Thank you! This tutorial had just solved my problem. Installed Linux on my 8GB pendrive and decided not to use it anymore, and found that my pendrive became only 1GB useable space with the rest of 6.87GB un-useable (unallocated)

  6. Thanxxxx…bro….you give me my Pen drive back…..
    Really helpfull…..Thanxxxxxx

  7. Thank you so much. I have been searching for hours and finally found your article. Very usefull. Thanks again!. My pendrive is back to full life!

  8. Great Help dude! No need to use Bootit too.

    Run -> dickmgmt.msc -> Delete Unallocated
    reinsert the pendrive -> diskmgmt.msc -> Create New Partition -> Voila! Gigs Recovered!

  9. Great Help dude! No need to use Bootit too.

    Run -> diskmgmt.msc -> Delete Unallocated
    reinsert the pendrive -> diskmgmt.msc -> Create New Partition -> Voila! Gigs Recovered!

  10. thnks buddy ………………its jst solved my prob
    really the best solution
    prob i got since 4Months, now i got my GBs back from 2.5 to full
    [Windows 7 + San Disk 8GB]

    thanks Again

  11. I had to use “format” instead of “flip removable bit” (Win 7 + DaneElec 2GB), but it ended up working just fine.



  12. moserbear pen drive readybroost tem
    problem how can solve it sir

  13. Hi,

    I see all the unallocated parts in disk management but no right click availabe on allocated parts. Tried to use bootit! but my flash disk is not in the drive list… Please help how to solve it…

  14. Thank you,thank you, I used format instead flip, but it worked fine
    Thank you you are lifesaver

  15. Thanks so much for this information…

    I have been hunting all over the web to regain the full drive space of my thumbdrive to no avail and then I stumble onto this website.

    I was surprised how easy it was and how well it worked…

    Thank you so much for posting this information

  16. i have tried flipping & reinserting the pen drive but still the problem is same. onyl thing i have done is “i have formated the pen drive before using this tool”

    anyy sugestions

  17. your great man…..thanks for your article,i got my 4GB pen drive back from 250mb.

  18. Its really awesome. Trick mentioned here really worked for me. I had a pen drive which had CDFS partition. which was blocking my 300 MB of space and i just wanted to use. You trick really worked. thanks a lot.

  19. Excellent. thanks for the tuturial.

    It worked on recovering the entire space of my flash drive

  20. My pendrive is display raw data and when i am trying to format it using windows its not allowing the same.i am trying to use Bootit.exe but its not detecting the drive.What should i do?
    Kindly mail me the solution.Thanks

  21. i have the same problem and am trying to repartition the USB drive (after being disappointed with the speed of Chromium OS). I have the following issues:-
    1. the partitioned portion which has the OS install on my USB drive does not have a volume name. So while the disk has the partition, it does not appear in the drives mentioned in BootIt
    2. BootIt crashes when i try to format the drive. any reason?
    any help would be appreciated!

  22. I got Solution !!!!!!! it is very easy.
    HI friends i made the same mistake. and my 4GB pen drive and 500GB external hard disk stopped working.
    First i got my usb drive back to4gb
    here is the method. i typed in run command box diskmgmt.msc then it shows pen drive below with capacity of 3.73GB and shows removable drive it also shows that my pendrive is unallocted space. so i clicked on format. and then select all the default setting which is window is offering(this time i have no choice i want to recover my space. nd beggers are not choosers hehehehe)
    and Wow my drive was recovered. with fat 32system.
    i only changed option fat 32 instead of FAT.
    Thats it i hope it will help you all
    Best of luck!!!!

  23. Chanceless Friends………..
    You all are really Great…… Nowadays if some one knows something They are hesitating to tell. But you Peoples are really Great Sharing everything and recovering others problems. Including my pendrive….

  24. thank u very much after searching for an hour…… last i got my usb back…..thanks alot

  25. Hi, I had tried this once and it worked like a beauty..but it doesn’t seem to be working now. I had formatted my my pendrive first before flipping the removable bit. Now no matter what i try, am unable to see the unallocated space from disk manager. Please help..

  26. i didnt work…..any more ideas how can i get back my lost free space..
    can it b done with linux?????

  27. BootIT didn’t do the trick for me ( Windows Vista running as Administrator ), but I found a fantastic solution that cleaned my usb drive and left it as a raw partition I could then manage quite easily, see the steps below . . .

    run command promt
    type diskpart
    hit enter
    type list disk
    hit enter
    find out number for your fdrive
    type select disk X
    hit enter
    (X being the number for your fdrive)
    type clean
    hit enter
    type create partition primary
    hit enter

    that’s it

  28. Hey Abhishek,

    Thanks so much for this post.. It really helped to recover my USB Pen Drive…

    Keep posting !!

    Best Rgds,

  29. Thanx. Linux stole my 4 gb and with Lexar, I retrieved the stolen raw space. Vowed not to use Linux again.

  30. Everyone follow steamboat instructions it worked for me. thanks a lot steamboat you saved my pen drive πŸ™‚

  31. thanks a lot….. i m mrinal … its very helpful in critical prblm… actly durng the tym of pc formting my pendriv was attchd with the maching…. and later it was nt workng… even it was showng ) space…. nw its ok…. thanks….

  32. hi
    whener i insert a pendrive the msg shows as “you need to format the disk in H drive before u can use it ”
    and then there a option for “format disk ” and ” cancel” if i click on format the messege comes as “check the disk and drive conected properly ake sure the disk is nor read only and then try again ”

    please please please help uregent , am note able to connect any usb not even my usb cable which i connect to my phone for transferr, … please revert as soonas posible

  33. STEAMBOAT THANK YOUUU!!! I tried everthing and your solution is the only one that worked. Tried for hours and hours with this BootIt and disk management!1 thank you sooo much

  34. Thank youuu !!!! STEAMBOAT …..your solution was the perfect with my drive…
    You are a genius…….want to keep in touch buddyyy !!!!
    Appreciating your helping mind and a big big thanks for your support dear….

  35. Hurrah! thanks Steamboat (this page) your disk management solution was simple and effective. I ha ve now recovered my 8gb usb drive to it’s full capacity.

  36. Thaks a Lot

    This tutorials helpe me to get unallocated space from my

  37. thanks…………………………………………
    It is helpful for me for get unallocated space. it is good

  38. thanks buddy!!!!!!!!!
    it recovered my lost pendrive capacity.
    u really rockssssssssss…………….
    keep helping….

  39. my problem is whenever i plugged my mp3 player to the usb port its
    showing that formatting now??
    i choose format it now bt then the system says

    “Windows cant format I
    check to see that the disk and drives are connected properly,
    make sure that the disk is not read-only,and then try again.
    For more information,search Help for read-only files and how
    to change them”

    i dont know whats the real prolem? i was copyng the songs to the
    mp3 player then suddenly this message appears.
    please help me to fix this problem.

  40. Dude! Thank you so soo much bro…I found exactly what I was looking for! God Bless ya πŸ˜€

  41. Thanks Dude..i got my pendrive back..i have Sandisk 16Gb and could bale to see only 31 MB after trying to make it as a windows i got all my 16Gb back.. Thanks so much my dear frnd.

  42. Thanks! This did the trick. I was searching all over with no luck resolving this issue. Great article.

  43. dint work 4 me… i tried flip and format but as soon as i re-insert my usb it shows as if nothin has happened to it…;'( plsplspls HELP!!!!!!!

  44. I used ‘format’ instead of flip.
    I got my 4gb drive back which was running one 1gb


  45. i have the same problem,i have 4 gig and it has reduce amusing window 7 i tried all the tricks but di dont work for me any help

  46. Thanks a lot. I’ve just saved a 8 GB pendrive which was being recognized as a 200 MB one (since it was the only partition read, without it being able to be reformatted or repartitioned using any conventional method). Thanks, thanks and more thanks.

  47. Thnx a ton man !!!
    I was searching continuously for 3 hours for how to get my SanDisk Cruzer 16GB back after an unsuccessful trial of Google Chromium but only your way has worked !!!!
    Better than using any other utility like Testdisk !!!
    Thnx again !! πŸ˜€

  48. Thank for this tutorial dude!!!! Worked fine with my 16Gb Kinsgston!!!!!!!!!!!! ;(

  49. thanks. you saved my day!
    my 8 GB USB drive was showing only 94 MB!
    huh windows!!!!

  50. This worked… cheers for making this tutorial and providing a valid download link to the file needed!

  51. Thanks everyone who contributed their bits…Steamboat’s solution worked best for me too πŸ™‚

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