Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I have a 4GB usb drive. Just now i have formatted it with fat filesystem. But after formatting its only showing 200MB instead of 4GB. I am using windows VISTA operating system. I am frightened.

Can anybody suggest any solution?

share|improve this question

migrated from stackoverflow.com Dec 28 '09 at 14:23

This question came from our site for professional and enthusiast programmers.

2  
Vista and FAT? That is frightening! –  zombat Dec 28 '09 at 6:15
4  
@zombat USB drives are almost always VFAT only (even on Vista). –  Sandeep Datta Dec 28 '09 at 6:36
    
For clarification, this is a memory stick, not a drive. –  JL. May 24 '10 at 11:41

8 Answers 8

I've had this problem before. I'm not sure what causes it, but I do have a fix. Here is what you do; be careful, this will format your flash drive or whatever drive you enter in step 3, so proceed at your own caution:

  1. Run command prompt as admin.
  2. diskpart which will put you into the Diskpart process
  3. select disk 1 (or whatever number that corresponds to your flash drive, unless you have other external drives or more than one hard-drive in your computer, this is almost always disk 1; to view all your disks use list disk when within the Diskpart process. It will show the disk # and the size of each disk found.)
  4. clean
  5. create partition primary
  6. select partition 1
  7. active
  8. format fs=fat32
  9. assign
  10. exit and exit again to close the Command Prompt window

This is what usually works for me, but as I mentioned before, be careful, I take no responsibility for lost data.

share|improve this answer
1  
I wish i could upvote this more than once –  sylvanaar Feb 1 '11 at 19:29
1  
This is the most proper and elegant solution thus far. Just make sure you format it with the proper file system (FAT or FAT32 for most USB drives, as this matches the sector size), or you may run into issues (i.e. extremely degraded performance) with the drive. –  Breakthrough Mar 6 '11 at 20:04
    
After you select clean, you can go into the Disk Management interface (right click on Computer and select Manage) to format. You must do a FAT32 format, after which Windows will see the size correctly and you can then format to whatever file system you want (e.g., NTFS or exFAT or whatever you have available). –  indiv Oct 24 '12 at 17:27
    
format fs=fat32 is fairly slow. you can use format fs=fat32 quick to make it much faster. –  Peter Meth Jul 10 at 21:12

This article might apply to your problem, although your USB is not large enough to fit the description:
Restore factory Hard Drive Capacity When HDD Shows up as 32MB

Here's what typically happens; a large capacity hard drive of between 500GB, 750GB, 1TB and 1.5TB suddenly appears to lose most of its capacity for no apparent reason. In many situations the capacity of the hard drive shrinks to 0.0GB or 32MB (and occasionally 32GB) and becomes inaccessible to the Windows Vista.

What's happening, to put it simply, is that the portion of the hard drive responsible for telling the computer how big it is, is mis-reporting that value. We don't have a good technical explanation for what causes this issue to randomly strike PC users, but suffice to say a portion of the drive firmware known as the LBA48, HPA and DCO records becomes corrupted.

This solution uses the Atola Technology HDD Restore Capacity Tool to fix the firmware - use with caution as it can brick the disk!

If the disk is still under warranty, it might be safer to use it.

share|improve this answer

I think you should check show/hide protected operating system files option. If you can see all protected operating system files, then you will find some folders like found00000, as hidden recover folder from your usb-drive after formating. Several times my friends have this problem and I ever delete these folders from their usb-drives and get full space again. So please try that first.

Another thing in the other hand, if you still couldn't get full space did you format your usb-drive in normal format? or format from cmd ? or format as system drive ?

I hope you can get full space when you format in normal way again and try which I tell you at first paragraph.

share|improve this answer

I actually had to use more commands inside the "diskpart" utility to get my 16GB corsair drive to function properly, after trying to flash it as a bootable drive for chromium.

I had to select each partition on the drive (there were several for some reason, of various sizes) and then delete them. I was then left with one partition of 16MB that would not delete without the "delete partition OVERRIDE" command.

Once I had deleted EVERY partition shown on the disk from the "list partition" command, (including the overridden one) I was then able to reformat the drive using the diskpart utility.

Hope this helps some others.

share|improve this answer

The origin of the problem is that the drive is formated on a Mac using a GUID partition table. Just reformat on a Mac using MBR partition table in the options of Disk Utility.

share|improve this answer

Are you sure the drive is 4GB? Does it show up as 4GB on other computers? Neither FAT nor Vista has any limitation that would prevent seeing a full 4GB of disk space on a USB drive.

share|improve this answer
    
FAT is limited, to 2Gb –  Bonus Feb 1 '10 at 15:54
    
The latest version of FAT16 (DOS 4.0) had a limit of 2GB. FAT32 goes up to 2TB HDs (with a limit of 2GB file sizes, though this is artificially limited in Windows for performance reasons). –  Chris S May 24 '10 at 13:17

If you actually formatted it with FAT (as opposed to vFAT) it would show up as much smaller. One of the advantages of vFAT is larger volumes.

Try repartitioning the drive using vFAT or NTFS.

share|improve this answer
    
You'd have to find a copy of DOS or Win3.1 to format a disk in the original non-vFAT formats. Vista will not produce those formats. –  Chris S May 24 '10 at 13:22

Are you sure there is just 1 partition on your memory card?

Kindly run diskmgmt.msc and post a screenshot here.
Also try to put the card in your phone and try to format it.(I am just making a guess here because you are formatting it with FAT)

For those of you wondering about FAT, some older phones can read memory cards formatted with FAT only.
e.g. Nokia's S60V2 phones

share|improve this answer

protected by studiohack Jul 10 '12 at 3:54

Thank you for your interest in this question. Because it has attracted low-quality answers, posting an answer now requires 10 reputation on this site.

Would you like to answer one of these unanswered questions instead?

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