Depends on the computer, some use F1, F2, DEL, ESC. When your first turn the computer on at the logo, you should see something somewhere either at the top or bottom of the screen saying press "what ever button" to enter setup..or something along those lines
F2
Hold down ESC while turning on via POWER button. The hit F1 when screen message tells you to do so!
F2
You press the B button
There should be a prompt that appears on the screen that tells you what button to press
Restart your computer and start pressing the F8 key on your keyboard. You need to press F8 before the Windows logo appears. If the Windows logo appears, you need to try again by waiting until the Windows logon prompt appears, and then shutting down and restarting your computer. Note: On a computer that is configured for booting to multiple operating systems, you can press the F8 key when the Boot Menu appears
X-Box 360: To wait, you need to press the the "Select" button. It is on the left side of the "Guide" button. There will be a meter that appears on your screen to ask you how long to wait.PS3: To wait, you need to press the "Select" button. It is on the left side of the "PS" button. There will be a meter that appears on your screen to ask you how long to wait.
Press and hold the >ll button on the front cover. Press the << button and smile! Press the >ll button to take the picture.
Press the fuel button until engine oil life appears on screen. Press and hold select button for five seconds. Oil life reset will appear on screen for 10 seconds. The system is then reset.
try to reboot your computer into safe mode.To use a Safe Boot option, follow these steps: # Restart your computer and start pressing the F8 key on your keyboard. On a computer that is configured for booting to multiple operating systems, you can press the F8 key when the Boot Menu appears. # Select an option when the Windows Advanced Options menu appears, and then press ENTER. # When the Boot menu appears again, and the words "Safe Mode" appear in blue at the bottom, select the installation that you want to start, and then press ENTER. Then click startclick runtype in msconfiguncheck everything under the startup tab except your antivirusand reboot
Most systems use the F8 key, while booting up, to start in Safe Mode. Immediately after power up, keep hitting the F8 key about once per second, until you come up in Safe Mode.
press f12 in the start up screen and that will access the boot menu. in the boot menu arrow key down and select your CD drive. enter and your booting to the CD. hope this helps.