Booting from Window needs that accessing BIOS. BIOS handle main hardware designs of PC. If PC takes you to desktop after startup, means you are booting from hard drive. If you want to boot from a CD, you must set CD/DVD drive as primary booting device. Reasons you want to boot from a CD contain reformatting system, installing and running antivirus programs, or to repair Windows.

Instructions

Step 1

Reboot PC. During splash screen, push button necessary to access BIOS. This is generally "F2" key. Many motherboards show this button on splash screen, though, it can also be found in motherboard manual.

Step 2

Go to "BOOT" sector of BIOS. Modify primary boot device from hard drive to CD ROM.

Step 3

Save settings and exit BIOS. PC will reboot.

Step 4

Put in disc that you want to boot from. On "Press any key to boot from CD" screen, push "Enter" key. CD will start to run. When you are completed, you can retrace these steps to set to hard drive back to primary boot device if you so select.