Tip: Boot from USB Key Addendum

Update 12/28/10: updated download links.

Previously, I posted a couple small guides on bootable USB drives, but recently I’ve been receiving reports that the utility mentioned in the guides is not working correctly. In all fairness, the utility was created only for use with a certain type of drive, and whoever made it hasn’t updated it, so problems with newer, unsupported drives are unavoidable. A newer, better utility is now available from HP, the HP USB Disk Storage Format Tool. (Don’t worry, it can be used with non-HP drives, verified with my Sandisk Cruzer Mini.) The HP utility will allow you to easily create a bootable USB drive, provided you have a disk available with the proper DOS system files, for example a Windows 98 boot floppy. If no boot disk is available visit bootdisk.com for some downloadable images, or simply use HP’s included DOS files.

To clarify the process, I’ve decided to post an update on how to manually make a bootable USB drive.

First, there are a few system requirements that must be clarified:

  • Obviously, your computer’s BIOS must allow booting from a USB device. Most recently manufactured computers allow this functionality.
  • You’ll also need a bootable floppy disk or CD. For example, you can use a Windows 98 CD or a Dell Resource CD.
  • You will also need a utility with the ability to create a master boot record, create and set active partitions, and format and transfer boot files. The DOS fdisk and format utilities that are present on the Windows 98 CD will handle this perfectly.
  • A USB drive that is capable of being made bootable. There are a few that have strange partition structures that do not allow for making bootable partitions. Contact the manufacturer if you’re not sure your USB drive is bootable.

Now that we have all the prerequisites taken care of, let’s get to how to actually make the drive bootable:

  1. Make the USB drive the first drive in the drive sequence. This is necessary because fdisk will not allow a partition to be active (bootable) unless it’s the first drive. This can usually be accomplished by plugging the drive in, powering on the computer, and going into the BIOS to change the boot sequence. If this is unsuccessful, simply disabling or unplugging the other drives in your system (except the CD-ROM, of course!) will do the trick.
  2. Boot the computer to a DOS shell from the bootable floppy or CD with the USB drive plugged in.
  3. Run fdisk.
  4. Set the primary partition on the USB drive to active by using “set active partition” (option 2) in fdisk. If you don’t already have a primary partition on the USB drive, use fdisk to create one.
  5. Exit fdisk.
  6. Reboot the computer to a DOS shell from the bootable floppy or CD with the USB drive plugged in.
  7. If you want, use the DOS command dir c: to verify the contents of the primary partition on the USB drive.
  8. Format and copy the boot files to the primary partition using the DOS format /s c: command.
  9. Run fdisk /mbr to write the master boot record to the USB drive without altering the partition table.
  10. Restart the computer, this time booting from the USB drive. If everything went well, you should see the C:> command prompt.

If everything didn’t go as well as planned, feel free to post in the forums for help.

About these ads

196 thoughts on “Tip: Boot from USB Key Addendum

  1. Thanks for the info. Boots like magic. I do have a question, do you know a way to have the drive letter assigned to the USB device to be something other than C: at boot?

  2. Wow, this was just what I was looking for.

    This handy little app isn’t even limited to USB key drives. I successfully created a boot drive with a CompactFlash card and a corresponding USB card reader.

    A million thanks!

  3. Nice information on the subject. Thanks a lot. However, I also need information on how to make a USB drive bootable WITHOUT formatting the drive. is there a workaround for this one?

  4. hi!
    i’ve got a iso image of a bootable CD, any idea to make a bootable usb key ?
    Thanks !

  5. I think a work around would be to use
    sys c:
    instead. Note, this requires the sys program…found in most win98 distros.

  6. Is it possible to boot from a Hard Drive (connected throug USB) wich already has Windows 2000?

  7. That should be a plug-and-play type situation. For instance, I’ve taken a hard drive with Windows XP out of a computer, popped it into a USB enclosure, and booted it on another computer to do some troubleshooting.

  8. can someone tell me if i did this properly (i have a sandisk cruzer mini) i downloaded a windows ME bootdisk image of bootdisk.com loaded it onto a floppy and then ran the utility – pointed to A: as the image for the bootdisk. it formated and copied stuff to my drive – but i cant seem to boot off it.

    I have a epox 4pea+ and its meant to be able to boot of USB stuff.

  9. Thanks so much for this information. Sandisk would be smart to post a link to this thread – its already brought them some business :)

    I have some additional information that might be helpful to some folks. I formatted my USB drive in XP using FAT32 and everything went fine. But everytime I tried to use the HP utility mentioned above, the utility indicated that the “media is write protected”. All I had to do was reformat the drive using FAT and the utility then worked like a charm.

    I can’t seem to get the utility to use anything other than the HP-supplied files, though. I tried MSDOS 6.22 (from floppies) and PCDOS 7 (from Norton Ghost’s boot disk utility) and the HP utility indicated that neither of these were valid files. Any ideas?

    Also, I have Windows98 Second Edition on CD and I am not sure how to create DOS boot disks without first installing the OS. Is there a way to do this?


  10. I am not having any luck getting fdisk to see my USB drive. I am using a SanDisk Cruzer. In my BIOS, i have for USB options to boot from USB-FDD, USB-ZIP, USB-CDROM, or USB-HDD, i have tried both the USB-HDD and USB-FDD and i am not able to get fdisk to see my usb drive, all it wants to see is my hard drive in my computer. Any help or ideas?

  11. Anyone know of a way to create a multi-booting USB key? i.e. on one USB key having the ability to choose to boot into win98 DOS vs booting into Dos6.22.

  12. Trying to make a bootable USB key that can boot to access Norton Ghost, and recover an image file from an internal (bay) second hard drive. My Dell only has one bay so using the moduler floppy drive and second moduler hard drive at the same time doesn’t work. Norton Ghost doesn’t give the option to make a bootable USB key; its only option is making a bootable floppy disk with the files that will access Norton Ghost. How can I make a bootable USB key that will access Norton Ghost?

  13. This was a lifesaver! I have an Athlon XP mobo that doesn’t have either a CD or floppy connected. I was able to boot and flash my bios with no problem using these instructions.


  14. Ok I have been working on this for a while. I have a bottable XP CD from winternals. I have been trying to get my USB key to boot XP. I can use the HP utility to boot to dos and load other OS’s but not XP. Does anyone have a dos boot loader app that can boot XP off a CD key?

    I can get DOS to boot, but I want to boot XP and I am having issues. I tryed making an ISO image and transfering it to my sandisk but it doesn’t boot, data is all their but no boot. I tryed using casper XP to copy drive to drive but it didn’t work either.

    Any insite whould be appreciated.

  15. What if you don’t have a Windows DOS CD or a floppy drive, and you run Linux exclusively.

    Does anyone no how you might use fdisk or other utilites from a Linux system to manually make a USB key bootable? Say using FreeDOS as an alternative?

    I’ve been trying with no luck, I can easily mount the key, format a bootable fist partition, but I think I’m missing the MBR part …

    Any help appreciated, thanks.

  16. Has anyone tried successfully to create a Linux boot USB Key? If so I would like to know how they did it as I am hoping to do something very similar but have not got my hands on a PC that will boot from the USB as yet…….

  17. Wait, i dont have a Win98 CD or floppy drive… how can i still do this with XP?

  18. If you get the “media write-protected” error using Windows 2003 Server, boot up XP (using VMWare works just as well) and the HP tool works flawlessly!

  19. I have a sandisk cruzer mini 128 and my machine is IBM T20. I called IBM and verified that the machine supports booting from USB. IBM has a bootable USB Floppy for this machine (which I don’t have) so this should also work. Anyway I am successfully able to create an active partion through the HP Utility but fdisk does not recognize my USB Flash drive. I’m using Win98SE boot disk…any ideas

  20. The files at HP can not be found, any idea, or does anyone have the program anywhere. ;-)

  21. There seems to be some confusion here. You can’t format a flash drive with FAT32. You can’t use DOS 6.x on any FAT32 device, it just doesn’t understand it.
    Lt. Worf, you’re in a chicken-and-egg situation. The flash disk has to be booted from before that will work. Booting ’98 and running SYS on the flash drive works fine, but you have to install the ’98 drivers first. I put 98SE on an old 540 meg HD and everything worked very well. I copied the whole Windows installation onto the CF card, but it hangs during startup. I didn’t really think it would work, but I’ll keep trying.


  22. This is a great thread, I was wondering if anyone had figured out how to make a Linux bootable key. I would love to be able to just plug a key in my notebook and have linux right there. I have tons of bootable linux CD’s I use for trouble shooting, but this would be just that much more cool.

    If anyone knows how please let me know, I have a bootable ISO of tiny linux ~228 MB but really don’t want it creating a ram drive, I’d think with the right sized drive one could do a regular install, and have the linux run striaght off the key.


  23. Hi,
    Does any one know why may the bootable USB hard drive I have made following Oliver’s method above will be have very slow connection now? What I wanted to do is to boot from a bootable USB HD, and then run Power Quest Drive Image from it to backup and restore. But know I see that the image backup to or image restore from C: (the USB HD) is very very slow. I know the connection can be faster because it will not be this slow if I use a floppy to boot to DOS and then mount my USB HD as the E: drive in DOS instead. Any insight will be very appreciated.

  24. Hi,

    Does any one know why may the bootable USB hard drive I have made following Oliver’s method above will be have very slow connection now? What I wanted to do is to boot from a bootable USB HD, and then run Power Quest Drive Image from it to backup and restore. But know I see that the image backup to or image restore from C: (the USB HD) is very very slow. I know the connection can be faster because it will not be this slow if I use a floppy to boot to DOS and then mount my USB HD as the E: drive in DOS instead. Any insight will be very appreciated.


  25. please i need help
    i have roshiba tecra 8000 labtop with win 98. the sytem crashed and i want to re install win98. the problem is that the laptop doesnt have floppy drive. how can i boot from an exteranl usb flopy which i find some how. i trie to enable usb in the bios but yet i codn’t open the flopy it says it is not ready.please help.

  26. Wow, thank you sooooo much for spelling out so simply and clearly how to make a USB flash drive bootable, you rule!! :)

    I have the Sandisk Cruzer Micro 256MB and the HP program worked like a charm. I was then able to perform a firmware flash on my new Dell that for whatever reason I STUPIDLY did not get with a floppy drive – and I ordered that way!! Duh!! lol I guess my brain was elsewhere that day.

    HOWEVER, at least I have this cool little device now.

    Thanks again for your expertise! Cheers…

  27. NOTE:
    ·My computers first boot devise is the USB flash disk.
    ·USB boot enabled
    ·USB flash drive is NTFS formatted

    When I tried to install win xp on my USB flash drive it could recognize the partion (NTFS format) which is on the USB flash drive but when I press enter to choose the partition to put win xp on it comes up with the following error message:

    “Your computers startup program cannot gain access to the disk containing the partition or free space you chose. Setup cannot install windows XP on this hard disk.

    This lack of access doesn’t necessarily indicate an error condition.
    For example, disk attached to a SCSI adaptor that wasn’t installed by your computer manufacturer or to a secondary hard disk controller, are typically not visible to the startup program unless special software is used. Contact your computer manufacturer for more information.

    On x86 – based computers, this massage may indicate a problem with the COMS drive type settings.
    See your disk controller documentation for more information.”

    Do I need to install a third party driver from a floppy disk to make the USB flash drive bootable by pressing F6 while the win xp CD is loading? If so where could I download one from?

  28. tesf, the Tecra 8000 can’t boot from a USB floppy. It came with a proprietary floppy drive that connects just below your PCMCIA cards. Do a search on eBay; you can probably pick one up for

  29. Everyone,

    Here is the problem with attempting to INSTALL Windows on a USB memory stick. With all removable media there is a “media type” flag set during the communication with the M$ storage stack. The installation prog’s will not allow you to install the OS on a removable Device. Why? Because aside from the various problems that could cause, it takes away sales from M$. They want you to install the OS on every piece of hardware you have and not on a simple $100 usb stick and then move it to different PC’s. Good luck, but AFAIK there is no workaround. This is also the initial problem with iSCSI.

  30. I have a new Dell M60 laptop that I bought a second HDD that plugs into the modular bay (the same bay the removable cd drive and the floppy drive uses). My goal is to load W2k on the new modular bay drive so I can boot from either it when I have it inserted (the BIOS supports this), or I can boot normally from my internal XP (IT supported) drive. I’ve got a catch22 – I need to load W2K on the new drive but to do so I have to remove my cd drive. I tried running W2K setup from my internal XP drive but it sees it’s an older OS and disbales the setup from proceeding. I have an HP8220e external cd burner (2000 vintage, USB ?.?) but when I set the Dell BIOS to boot from the “USB storage device” it doesn’t see the cd drive. My floppy drive has a USB adapter cable, and I can run the W2K setup diskettes from it. I was hoping I could boot from them and it would switch to my HP ext cd during the setup process, but no such luck.

    My alternative is to physically open the new modulay bay drive cassette and swap the new drive with my fixed drive temporarily to load W2K on the new drive. But that’s admitting defeat, and I’m not sure how the BIOS will handle it since both drives will have the same addressing? Any ideas on 1) how to boot from my HP external drive or 2) what will happen on bootup if I have two drives with the same addresing?

  31. I am using Windows XP Pro and I got the same “media is write protected” message. I found that it was because I had my USB Key drive set as drive (B:). I changed the drive letter to (H:) and I was able to format the drive using FAT, FAT32, and NTFS. To change the drive letter in Windows XP Professional, right-click on the “My Computer” icon and select “Manage”. When the Computer Management window opens, select “Disk Management”. Right-click on the USB Key drive and select “Change Drive Letter and Paths…”. Click the “Change” button and assign the drive letter that you want to use for your Key Drive. This should also work with Windows XP Home Edition. (I only recommend changing the drive letter for removable drives such as USB Key/Thumb drives, CD-ROM drives, etc.)

  32. It works great but how can i access my fat32 partition that is (c:\) because the usbdisk is also c:\?

  33. I had the same problem with fdisk not recognising my usb hdd.
    For me the solution involved unplugging the IDE cable from all other HDD’s in the computer.

    Apart from other peripherals (mouse, keyboard, etc) i only had the usbdrive and FDD connected.
    booting from the FDD (using a win98se bootdisk) and running Fdisk i was able to see the usb drive.

    this may help?

  34. ah, booting from the floppy to use fdisk was the innovation that I hadn’t thought of. Nice.

  35. Lt. Worf,
    I had to physically disconnect my HD before FDISK was willing to consider the USB drive a fixed disk, regardless of what boot order I set. Once I did this things went very smoothly!

  36. Does anyone know if I can make Knopix 3.4 boot off an USB2 1 Gig key???? Can the HP utility you suggested in the logs work?

    Please advice

  37. is it possiable to get a bootable CD
    onto a usb key and work?

    any information on doing this would be great

    also have had no luck getting an activie partion on my usb even tryed disconecting my hard drives and had no luck fdisk would not find my usb drive
    i am using a iomega min 512mb

  38. I have a SanDisk Mini Cruzer 512MB

    The HP utility will work with a DOS boot disk created by XP SP1a, but not with a MS_DOS v7.1 boot disk (from newdos.yginfo.net).

    behaviour is consistent independant of FAT/FAT32

    Maybe the version of DOS is important?

    I use USB-HDD, which is what *should* be used to HP Utility & FDSIK method.


  39. In DOS 6.22 environment, after I selected in BIOS to boot on USB-CD, inserted a bootable CD that contains the USBASPI.SYS and USBCD.SYS drivers, I see an attempt to boot using the USB-CD but fails at the point when the USBCD.SYS driver is installed.

    The error I am getting indicates that the command interperter is lost. On the other hand , using the same boot files and drivers from floppy works fine and the access to USB-CD is accomplished too.

    Any idea how to make the USB-CD bootalbe under DOS.

Comments are closed.