How to change boot order to start from CD or USB

Often, we need to change a PC or laptop’s boot order to start from CD, DVD, USB, external hard drive or floppy disk.  It’s not difficult to do this but timing is important.

Turn on or restart your computer and watch for a message during the startup screen about which key to press.  It’s usually Del, F10 or F2 and you need to press this key as soon as you see the message on screen. The window of opportunity is really quite small – about 2 seconds – before the computer loads the operating system (eg Windows).

Now, if you have done this correctly you will see another screen loaded.  If you have gone on to the Windows load screen, you will need to wait, shutdown and try again. Don’t be tempted to turn the computer off on the button or at the wall socket as this will cause even worse problems.

The new screen you see is called the BIOS screen. It will look like this, although not exactly as many manufacturers will have different setups.


This allows control over the hardware in your PC such as CD/DVD, USB, memory, processor, hard disk drives etc. It is generally a blue background and navigation is done using the keyboard cursor keys (the arrows) and not the mouse. Navigate to the ‘boot’ area and change the order of the boot sequence so that your CD boots first. In the example above, the hard disk boots before the CD ROM so this would need changing. Save and exit the bios screen. This restarts the computer. Make sure you have a CD in the drive that you wish to boot from. Do likewise if you wish to boot from USB (some older BIOS systems do not support USB booting).

PCRepairMan’s top tip:

Note that many BIOS systems look confusing at first but they usually have helpful prompts for how to navigate and change values stored in them. In the screenshot above, you can see the bottom of the page shows Arrows to move, Enter to select, Page Up/Down to change values, F10 to save etc.

With a new boot order set, your computer will look to that device to start every time. This can be a problem after the fix, when the PC is set to boot to usb and you plug in a non-bootable USB, for example a printer. The BIOS can look at the printer and hang, waiting for it to do something.  If this happens, simply change the boot sequence back to your hard drive first and this will resolve it.