27

I already tried FORMAT /FS:FAT, diskpart, Disk Management and HP USB Disk Storage Format Tool.

Do I really need to buy a smaller capacity drive? Can't a formatting tool ignore the area beyond 2 GB?

My Asus netbook's BIOS update requires the USB to be formatted as FAT16, and I couldn't get the various Asus BIOS update utilities to work.

Peter Mortensen
  • 12,326
William C
  • 271

5 Answers5

39

Disk Management and DISKPART don't let you delete partitions on removable media. But you can use DISKPART's clean command to nuke it and start over. Here is a series of commands that worked for me:

DISKPART> list disk

  Disk ###  Status      Size     Free     Dyn  Gpt
  --------  ----------  -------  -------  ---  ---
  Disk 0    Online        40 GB      0 B
  Disk 1    Online      7538 MB      0 B

DISKPART> select disk 1

Disk 1 is now the selected disk.

DISKPART> list part

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    Primary            500 MB  1024 KB

DISKPART> clean

DiskPart succeeded in cleaning the disk.

DISKPART> create part primary size=500

DiskPart succeeded in creating the specified partition.

DISKPART> active

DiskPart marked the current partition as active.

DISKPART> format fs=fat quick

  100 percent completed

DiskPart successfully formatted the volume.

DISKPART> assign

DiskPart successfully assigned the drive letter or mount point.

This creates a 500MB FAT partition as the only one on the disk. list part is only used to make sure I selected the right disk (and the Size shown was from a previous attempt; yours will say something else closer to the full size).

Ken
  • 8,185
3

There isn't any way to format a FAT16 partition larger than 4 GB (2 GB under Windows). Use a partitioning tool to repartition the drive (you may need Linux for this).

Peter Mortensen
  • 12,326
Ignacio Vazquez-Abrams
  • 114,604
2

Thanks Ken for your suggestion using diskpart. I needed this to do a firmware update to an old Sharp Aquos tv (it would recognize the update, but when it tried to flash it couldn't find it). After converting my 8GB USB to a 512 mb FAT disk, it updated fine.

For anyone who only needs to do this temporarily, here are the steps that worked for me to get it back to its original size. Note that basically I left the size variable off. I also knew I wanted to format it as fat32, but I'm suspicious if you leave off the fs part, it will format it appropriately.

DISKPART> list disk

  Disk ###  Status         Size     Free     Dyn  Gpt
  --------  -------------  -------  -------  ---  ---
  Disk 0    Online          223 GB      0 B
  Disk 1    Online         7657 MB      0 B

DISKPART> select disk 1

Disk 1 is now the selected disk.

DISKPART> list part

  Partition ###  Type              Size     Offset
  -------------  ----------------  -------  -------
  Partition 1    Primary            512 MB  1024 KB

DISKPART> clean

DiskPart succeeded in cleaning the disk.

DISKPART> create part primary

DiskPart succeeded in creating the specified partition.

DISKPART> active

DiskPart marked the current partition as active.

DISKPART> format fs=fat32 quick

  100 percent completed

DiskPart successfully formatted the volume.

DISKPART> assign

DiskPart successfully assigned the drive letter or mount point.

DISKPART>
Shygar
  • 383
0

Linux mkdosfs for Windows NT/2K/XP ranks pretty highly on Google when searching for "mkdosfs".

Seems like exactly what you're looking for.

ephemient
  • 25,622
0

FAT 16 only supports 2 GB or less.
But you can force format SD card that bigger than 2GB as a 2GB card.

  1. Disk Utility format card by FAT32
  2. e.g. newfs_msdos -F 16 /dev/disk2s1 (path to SD Card device)/(SD Card device number)
emj365
  • 101