How to boot an USB drive from a legacy BIOS

[es20490446e]

Many older computers have issues booting from external USB drives, and booting from CDs is usually slow and prone to errors in modern operating systems.

Here's how to boot from an USB drive despite of how old the computer is:

1. In the BIOS, disable Legacy USB Storage.
2. In the BIOS, enable CD as first boot device.
3. Download and burn in a CD the Plop Boot Manager.
4. Write your favourite operating system into an USB drive.
5. With the CD in the CD reader tray and the USB drive plugged in, reboot .
6. In the screen that will appear, choose "USB".
7. If that doesn't work, with USB selected in the menu, press shift + enter.

[mirh]

Ohh, good old plop.

I used to have it on a floppy disk (to boot to an USB drive) until just last year on an ancient pentium 4

[mbb]

Good old plop indeed. I still use to boot my Windows partitions from raw images and on an old laptop which can't boot from USB directly. I added a small note to the end, hope you don't mind.

EDIT: alternatively the system can be installed on a raw image to a disk, and then the disk can be installed on a different machine to boot it. You then have to remove virtualbox modules and install video drivers correctly. I used this method twice because my old laptop's DVD drive isn't working and I forgot I needed plop to boot it (I wiped the drive and then I had no way to boot the machine).