What are the most common reasons for a computer to fail to boot from a CD or USB drive?

1 BIOS Settings

One of the first things to check is your BIOS settings, which control how your computer starts up and interacts with the hardware. You can access the BIOS by pressing a specific key (usually F2, F10, or Del) when you turn on your computer. In the BIOS, you need to make sure that your CD or USB drive is recognized by the system, and that it is set as the first boot option in the boot order. If your CD or USB drive is not detected, you may need to enable legacy or compatibility mode, or disable secure boot or fast boot options. If your CD or USB drive is detected, but not listed as the first boot option, you need to move it to the top of the boot order, and save the changes before exiting the BIOS.

2 Media Quality

Another possible reason for a computer to fail to boot from a CD or USB drive is the quality of the media itself. If your CD or USB drive is scratched, damaged, corrupted, or outdated, it may not work properly or at all. To avoid this, you should always use a clean and reliable CD or USB drive, and verify its integrity before using it. You can use tools like Rufus or Etcher to create a bootable USB drive from an ISO file, and check the MD5 or SHA checksum of the file to ensure it is not corrupted. You can also use tools like ImgBurn or CDBurnerXP to burn a bootable CD from an ISO file, and choose a low burning speed to reduce errors.

3 Hardware Compatibility

A third common reason for a computer to fail to boot from a CD or USB drive is the hardware compatibility. Some older computers may not support booting from USB drives at all, or only from certain types of USB ports. Some newer computers may require specific drivers or firmware updates to boot from certain CD or USB drives. To avoid this, you should always check the specifications and documentation of your computer and your CD or USB drive, and make sure they are compatible with each other. You should also update your BIOS and drivers to the latest versions, and use a USB 2.0 port instead of a USB 3.0 port if possible.

4 Software Configuration

A fourth common reason for a computer to fail to boot from a CD or USB drive is the software configuration. Sometimes, the CD or USB drive may contain an operating system or a tool that is not compatible with your computer's hardware or existing operating system. For example, if you try to boot a 64-bit operating system on a 32-bit computer, or a Linux operating system on a Windows computer, you may encounter errors or compatibility issues. To avoid this, you should always choose a CD or USB drive that matches your computer's architecture and operating system, and follow the instructions and requirements of the software. You should also backup your data and create a restore point before booting from a CD or USB drive, in case something goes wrong.

5 User Error

A fifth common reason for a computer to fail to boot from a CD or USB drive is the user error. Sometimes, you may simply forget to insert the CD or USB drive, or press the wrong key, or choose the wrong option, or follow the wrong steps, when you try to boot from the external media. To avoid this, you should always double-check your actions and follow the instructions carefully. You should also consult the online forums, guides, or support pages of the software or the hardware you are using, if you encounter any difficulties or doubts.

6 Malware Infection

A sixth common reason for a computer to fail to boot from a CD or USB drive is the malware infection. Sometimes, your computer may be infected by a virus, a worm, a ransomware, or another malicious program that blocks or interferes with the boot process. For example, some malware may modify the boot sector, the master boot record, or the boot configuration data of your hard drive, and prevent your computer from booting from any other media. To avoid this, you should always scan your computer regularly with an antivirus or antimalware program, and keep it updated and protected. You should also avoid opening suspicious attachments, clicking on dubious links, or downloading untrusted software. If you suspect that your computer is infected, you should try to boot into safe mode, or use a rescue CD or USB drive that contains a malware removal tool.