Computer will not boot up. as soon as I press power button. starts up, no picture on screen, humming sound and cuts off. what are some possible problems causing this

Starting up in Safe Mode Follow these steps to start up into Safe Mode.

1. Be sure your Mac is shut down.
2. Press the power button.
3. Immediately after you hear the startup sound, press and hold the Shift key. The Shift key should be pressed as soon as possible after startup, but not before the startup sound.
4. Release the Shift key when you see the Apple logo appear on the screen.

After the Apple logo appears, it may take longer than usual to reach the login screen. This is because your computer is performing a directory check as part of Safe Mode.
To leave Safe Mode, restart your computer without pressing any keys during startup.

Perform a Hard Reset Do these actions first to clear all temporary setting before troubleshooting the problem.Disconnect all peripheral devices and remove all USB devices and media cards.Disconnect the AC power adapter, remove the battery, and then press and hold the power button for at least 15 seconds to drain residual charge.Reconnect the AC power adapter (do not connect the battery), press the Power button and look for the LEDs to blink or glow, and listen for the sound of a disk drive and fan turning.Perform each recommended corrective action and then attempt to restart the computer.Symptom 1: LED lights do not glow, display is black, no fan or drive sounds are heard, and computer does not startIf LEDs do not glow or blink when AC power adapter is attached and power button is pressed, there is no power available to the notebook Check AC adapter wiring and power connection to the notebook Connect a different AC power adapter and remove battery, then restart notebook.Connect a different battery and disconnect AC power adapter, then restart notebook Symptom 2: LEDs blink or computer beeps but does not start Blinking LEDs or beep tones indicate a hardware failure during the pre-start up testing Count number of blinking LEDs or beeping tones to help with diagnostics testing Symptom 3: LEDs glow, fan noise may be heard briefly, display remains black, and computer fails to startup or boot Usually occurs if a component is installed incorrectly, or there is a device conflict or failure Connect an external monitor to check if the problem is the built-in LCD display or graphics card Remove all CD/DVDs, SD cards, USB devices, peripherals and do a Hard Reset If memory or hard drive components were replaced, reinstall original component Remove memory modules and replace one-at-a-time Remove and reseat hard drive If possible, turn on power, press F10 to enter BIOS mode, and run Memory Test and Hard Drive Test On newer notebooks, turn on power, press Esc to enter UEFI mode, and run Memory Test and Hard Drive Test If possible, turn on power, press F8 to enter Windows Advanced Boot Options , and select Repair Computer option, or enter Safe Mode and run Memory Diagnostics If all other methods fail , but computer can boot to BIOS, use recovery disk to recover the computer to original condition Symptom 4: Computer may display an error message on a black screen during startup or boot Search www.microsoft.com for terms in error message Search www.hp.com for terms in error message

If possible, turn on power, press F10 to enter BIOS mode, do the corrective actions listed under Symptom 3 to run memory and hard drive tests.

Symptom 5: Computer displays a blue screen or continually re-starts After an error message is displayed, you can usually bypass the error and continue to run the notebook in Safe mode to install an updated BIOS or driver.

• Search www.microsoft.com for terms in error message.
• Search www.hp.com for terms in error message.
• If possible, turn on power, press F10 to enter BIOS mode, and run diagnostic Memory test and Hard Drive test .
• If possible, turn on power, press F8 to enter Windows Advanced Boot Options , and do one or more of the following:
  • Select Disable automatic restart on system failure to view error message.
  • Run Repair Your Computer .
  • Run Last Known Good Configuration .
  • Select Boot into Safe Mode and then select Run a Microsoft system restore .
  • Select Boot into Safe Mode and then select Uninstall recently installed programs .
  • Select Boot into Safe Mode and then run Windows Update .

Symptom 6: Computer displays the Windows logo screen and stops responding If no error message displays, turn on power, press F8 to enter Windows Advanced boot options ,and select Disable auto-restart to view error message.

• Search www.microsoft.com for terms in error message.
• Search www.hp.com for terms in error message.
• If possible, turn on power, press F10 to enter BIOS mode, and select Restore the BIOS defaults (F9) .
• If possible, turn on power, press F10 to enter BIOS mode, and run Hard Drive Test .
• If possible, turn on power, press F8 to enter Windows Advanced Boot Options , and select Last Known Good Configuration (Advanced) . .
• If possible, turn on power, press F8 to enter Windows Advanced Boot Options , and select Boot into Safe Mode and then Uninstall recently installed programs .

Update Computer After Resolving A Problem When the computer starts into Windows normally, you should install the latest updates and patches to prevent other start-up problems.

During the boot process you will see on the screen to press a certain key to enter setup
Press and hold that key during the boot up process to enter BIOS you can load failsafe defaults or load optimized defaults ,press escape then press f10 to save to cmos to restart
or
During the boot process tap the f8 button three times this will boot into safe mode where the only things working will be your mouse and keyboard enabling you to attempt to repair your computer
Also you might try
Turn Off the computer, now as soon as you hit the power button, keep on holding "Alt" key & keep on tapping "F10 key,ie: Alt+F10, it will open the recovery console ,select full factory restore and follow on screen instruction. (Note:this will erase all datas on the computer)
hope this helps

Turn Off the computer, now as soon as you hit the power button, keep on holding "Alt" key & keep on tapping "F10 key,ie: Alt+F10, it will open the recovery console ,select full factory restore and follow on screen instruction. (Note:this will erase all datas on the computer)

Here are a few things you can do or try

Restart the computer. If you are already in Windows, you can do this from the Windows Start menu, go to Turn off computer and click Restart. As the computer restarts, watch for a progress bar at the bottom of the screen. press F8 about once every second. Immediately press F8 before the progress bar reaches the right side of the screen. From the Windows Start-up menu, highlight Safe Mode and press Enter. Wait for your desktop to appear, and then make the necessary repairs (for example, uninstall programs or devices). When the repairs are done, restart the computer, and allow it to boot normally.

Alternate:

From the Windows Start menu, click Run. In the Open field, type MSCONFIG and click Ok. On the BOOT.INI tab, check /SAFEBOOT.

Click Restart when prompted.

Turn Off the computer, now as soon as you hit the power button, keep on holding "Alt" key & keep on tapping "F10 key,ie: Alt+F10, it will open the recovery console ,select full factory restore and follow on screen instruction. (Note:this will erase all datas on the computer)

or

During the boot process you will see on the screen to press a certain key to enter setup

Press and hold that key during the boot up process to enter BIOS you can load failsafe defaults or load optimized defaults ,press escape then press f10 to save to cmos to restart

click start all programs accessories scroll to system tools from there you should see a system restore click next a sytem date should open up select the date you want to restore your computer to or if you want a full factory restore or

Turn Off the computer, now as soon as you hit the power button, keep on holding "Alt" key & keep on tapping "F10 key,ie: Alt+F10, it will open the recovery console ,select full factory restore and follow on screen instruction. (Note:this will erase all datas on the computer) or

During the boot process you will see on the screen to press a certain key to enter setup

Press and hold that key during the boot up process to enter BIOS you can load failsafe defaults or load optimized defaults ,press escape then press f10 to save to cmos to restart

helps don't forget to vote

Sounds like the boot sector is corrupted or missing most like due to a virus. Boot from your Windows disk and reinstall your OS.

Boot Priority on Dell Latitude 100L

1. Turn On Your PC
   Have you ever noticed the messages that pop up on the screen as soon as you turn on your PC? These messages tell you a key combination you can press to enter "Setup" or the "BIOS." Watch your screen and see if you can read what keys to press.
   
2. Press the Keys to Enter Setup Mode
   If you did not see a message telling you what keys to press, try tapping the following possibilities as you turn on the machine:
   
   • Esc
     
   • F2
     
   • F12
     
   • F10
     
   • F1
     
   After pressing Esc or other key, you will most likely see instructions telling you how to enter "Setup Mode". Follow those instructions.
   On some computers, you must hold down the key before you press the power button to turn on the computer. For example, if you are converting a Toshiba laptop to a Linux Workstation, you must hold down the Esc key and then press the power button. The computer then asks you to press F1, and you can then set the "Boot Priority."
   
3. Using the Arrow Keys, Choose the "Boot," "Boot Order," or "Boot Priority" Option
   The menu of choices you see will be different for different kinds of computers. Remember that the choice you want is the "Boot" order or "Boot Priority." On some computers, this is called the "Start Up Options" or "Start Up Sequences." You are going to change where the PC will look for boot information when it starts up. (CD-ROM, HARD DRIVE/HDD, LAN, FLOPPY, USB). If you wish to boot from your Hard drive, then select it as your First Priority.
   
4. Using the instructions on the screen, save your settings and start up your PC. The PC must boot from the HDD. Regrds
   

Hi. Turn the computer on and press F8 when you see the toshiba screen. Select safemode then press enter. open the System Config Utility (msconfig) by pressing Start, Run (XP), or type the word msconfig then press enter for Vista.

Disable all start up items and restart your machine... See if it starts and boots to windows.

^_^

HI there will you please follow the steps.

1. After press power button for turn on press F8 key.
2. You will find few option there. Just select these mention option " Last know good Configuration ...." use by your up/down arrow on your keyboard.
3. Press enter there.
4. your will see the system asking you for which OS you want to use. If you have only one OS then just press ENTER there or select the OS and Enter.

If no luck after that all then you have to format your OS & installed it again.

During the system bios boot press and hold ALT + F10, that should start you into the system recovery options.

Can you hook up an external monitor to it and see it just fine there? If so, then one of two possibilities: Either the LCD inverter is bad, or the screen itself is bad. Oh, it could be just a loose wire from the screen to the motherboard also.