Force Boot Devices

Computer system can be booted from several different devices. These include optical drives, hard drives, flash drives as well as other types of flash memory such as SD Cards, etc. Purpose behind booting from these devices can be installing operating systems, running operating systems, running alternative systems, performing updates to firmware and the hardware as well as running various diagnostic tools. This guide will teach you how you can boot from different devices on demand.
 
Things to know

Every computer system understands the meaning of a boot record and a bootable device. A device with no bootable record cannot be booted into.

This guide will focus on forcing specific devices to be booted from on a single basis in case of diagnostics or other purposes.

There are 2 ways you can adjust bootable devices. You can either do it the long way by adjusting the order of devices in the Motherboard BIOS, or like most motheboards noawadays you can press an F# key to envoke a Boot Menu, which allows you to choose what you want to boot from.

The benefit of booting this way is that it doesn't interfere with your BOOT configuration. If you already prefer your internal HDD to be the main device, then that will always stay the case. Perfoming a quick boot menu you will be able to make a change one time without making permanent changes that require modification when you're done.

 

Specifics

Each motherboard manufacturer has their own F# key that they assign to the boot menu. Most common ones are as follows:

Asus - F8

Gigabyte - F12

Intel - ESC or F6

MSI - F8 or F12

As you can see, it's typically the F8, or the F12 key for majority of popular desktop boards out there. Things that you have to keep in mind is first, the window of time that the system allows the button to be pushed can sometimes be short, as far as 1 second. Therefore the most recommended way of envoking this menu is the moment you start the system, you should begin to press the correct F# key very fast, repeatedly.

You also have to keep in mind that wireless keyboards are known to sometimes add lag to the process, making it nearly imposibble to enter the menu or even enter the BIOS. If this is the case, you must use a wired keyboard (USB or PS2) in order to access the menu in time.

Some systems may go through significant amount of screens, loading time and information before they finally show the boot menu.

Also, if you're booting from a removable device, you must make sure that this device is connected before turning on the system. Plugging it in while the system is working will not get it detected properly. Restart or complete shut down may be required in order to make some devices visible.

Finally, most motherboards don't have ability to provide proper description of the device they're plugged into. Sometimes you must do a little bit of defective work. For example a Western Digital Hard drive may not show up in the list as "Western Digital Hard drive", but it may contain numbers and letters that can give it away. For example, if you know that your drive is model 2500AS, then seeing something like WDC2500AS indicates the drive you're looking for. Sometimes on the other hand you will get lucky and the motherboard will display the full name of your device. This is a rare occasion and it usually only happens with flash drives.

By selecting a device from this menu you do not end up changing your order. Next time your system starts up, it will default to whatever the order designated in the BOOT menu inside the BIOS.

However, some of the newer boards have been known to modify the BOOT menu if flash devices are added while the system is off. This feature is usually refered to as USB Priority and can be turned off for some motherboards. Please refer to your manual for instructions on how to do that in case that's what's happening to your system.

Lastly, some bootable media may require additional user input. For example Windows OC CD may sometimes require additional key press after being forced to boot from the optical drive. Usually you will see a message that says "Press any key to boot from DVD...". You must press any key (space for example) within a short amount of time, typically 3 seconds. If you skip this time, the boot will cancel and it will jump back to default. 

*Disclaimer: AVADirect and its Staff are not responsible for any damage to software/hardware, loss of data or personal injury by following our How-To guides. These guides are provided only as an aid to help you troubleshoot system problems. If you do not feel comfortable performing these steps its always best to send in your system to a local repair shop or contact an appropriate technical support line for additional assistance.