I need to boot Ubuntu in a computer (computer A) with no CD. I have a 16 Gb pendrive with a live Ubuntu version. The pendrive works in at least two newer computers. Computer A boots from a 2Gb pendrive right. So it's likely a BIOS issue.

But it's quite inconvenient to always carry two pendrives, how can I made the older computer boot from the bigger drive?.


  • Repartitioning the drive doesn't seen to work.
  • I noticed than the 16 Gb pendrive is seen like a external zip drive by the BIOS, while the smaller one is seen as a Hard Disk. Likely related.
  • Looks like I would need to carry a second stick. Thanks to all. Aug 13 '10 at 16:39

Very often you can run in to problems with high-capacity usb-sticks and old hardware, most of the time the it is only BIOS that seems to be the problem. So if the BIOS can be upgraded then try that.

The only other solution (afaik) is to kickstart usb-booting from a floppy-disk, and that is not really an alternative to carrying two sticks.

If you are interested in the floppy method you should look at the grub documentation, and this brief guide on how to dd the precompiled image for pendrivelinux, after writing the disk you might have to edit the grub-config file on there.

  • Thanks, but most of the computers don't have a floppy disk either. I'm better carrying two sticks than a stick and a external floppy drive ;). Aug 13 '10 at 8:41
  • Try to find out if the BIOS can be upgraded. Aug 13 '10 at 8:42
  • No floppy, no windows utility, no easy BIOS upgrade :( Aug 13 '10 at 10:03
  • without having something other than a usb-plug to kickstart from you don't have any other choice than to install from a smaller usb-drive. and I wasn't refering to the windows utility but the section titled "Creating a Boot Floppy to Boot Pendrive Linux from a USB device". Aug 13 '10 at 11:47
  • I was talking about updating the BIOS. I only know 3 ways, boot from a floppy disk, boot from a FreeDos CD, use some nice windows utilities that some manufacturers supply. Aug 13 '10 at 13:34

A lot of BIOSes, even quite recent ones, can't boot from a USB device that has partitions. In Linux terms, the filesystem must be directly on /dev/sd?; the mere existence of a partition table makes the BIOS give up.

If this is an older BIOS, then in addition the bootloader may need to live entirely near the beginning of the disk (typical limits are 512MB, 2GB or 8GB).

  • Thanks, great insight. Unluckily it didn't make any difference with that computer :(. Aug 13 '10 at 16:40
  • If you haven't tried it already, try sticking the 16 GB stick in Ubuntu and shrinking the partition down to 2 GB using gparted. I know you said, "Repartitioning the drive doesn't seen to work", but you didn't go into details. If this works, you can format the remainder of the drive to something like ext3 and windows will never know that space is there.

  • You could get a Compact Flash to IDE converter (both laptop and desktop IDE plugs are available), and a flash card and put your OS on that. Of course, instead of two pen drives you have to open every case and hope for a spare PATA socket, so I don't see how that helps


In 2007 I installed Xubuntu on a 20GB hard drive on an older computer. When I booted up, I got GRUB error 18.

Reading about GRUB error 18, I learned that it meant my Ubuntu partition was too large for the BIOS to handle.

The solution was to create a 100MB EXT3 partition and set it to be mount as /boot.

How to do the same with a flash drive, I'm not sure.

  • Repartitioning doesn't seem to work. I don't really believe that this is the problem as it a not soo old computer. It can boot from usb, it has usb that novelty !!!! ;). Aug 13 '10 at 13:36

With http://www.plop.at/en/bootmanager.html you can create a cd that will allow you to boot the usb. You would have to carry both the cd and stick with you though.

  • ​In order this solution to work, in the BIOS, I had to disable Legacy USB Storage. Oct 11 '17 at 5:38

Try Unetbootin it is better for booting older computer from USB stick. I first used Yumi boot it worked fine for newer computers but not old. Then I installed Unetbutin and the old computer boots ok. If you favor a Linux computer it is also possible to make a startup on a USB with an ISO file with Ubuntu startup program.


The best way to create a USB multiOS bootable is with Yumi and has to be on FAT 32.

Firstable add the unlisted ISOs , and secondary the main ISOs example Ubuntu 11.04 x86, Ubuntu 11.04 x64.

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