WHEN COMPUTER STARTS I GET A BLUE SCREEN AND THEN IT REBOOTS

A very dark blue screen on a laptop that otherwise appears to be "on" is a sign that the backlight on the screen portion of the computer may be burned out. You can test this by shining a flashlight on the screen. If you can see your desktop icons, the backlight is burnt out. Replacing a bad backlight is not a do-it-yourself task unless you are comfortable doing delicate electronic repairs and have the design schematics for your model in hand. Your safest course of action will always be to take the laptop to a professional repair depot. There is one alternative repair option available if you're not comfortable doing surgery and a trip to the repair shop is not in your budget. Replace the entire screen module, case and all.

Doing Surgery Yourself

1.Remove the battery from the laptop. With the laptop model schematics in front of you, use the small Phillips screwdriver to separate the monitor from the laptop base. The schematics will indicate how to uncover the monitor hinges and free the monitor. Handle the screen gently because it will still be tethered to the base by a group of wires.
2.Remove the plastic case covering the "power bar" on the upper part of the laptop keyboard base. Refer to the schematics to find the way to release this cover and lift it off the keyboard. You'll see a group of fine wires leading back to the monitor. Unplug this cable so the monitor is now free from the base.
3.Follow the schematics to remove the casing covering the monitor screen. Be forewarned that the design of a laptop monitor "under the hood" is complex and delicate. Don't force anything. Don't experiment. Take frequent photographs of each successful disassembly stage so you can have some hope of getting it all back together again correctly.
4.Find the slim fluorescent backlight instrument behind the glass layers of the screen. Unplug it from the tiny cable receptacles and remove it. Insert the fresh backlight fixture and reconnect it to the cable plug.
5.Restore the screen assembly and the casing using the schematics and your reference photographs. Plug the screen back into the laptop base at the power bar. Don't reattach the screen hinges to the base until after you have tested it by booting the laptop. If the test is successful, turn the laptop off and connect the screen to the base unit at the hinges.

Alternative Repair

1.Purchase an entire screen-and-case assembly for your laptop make and model. Many intact assemblies are available online for reasonable prices. You will usually pay slightly less for an entire screen-and-case unit than you would for a professional repair on just the backlight alone so this could be an economical alternative for you. You can save even more money by purchasing as "Used but Good" unit, rather than a new unit.
2.Remove your old screen following the previous section's Step 1 through Step 3.
3.Plug the new screen-and-case unit into the laptop base. Follow the schematics and your photographs and thread the monitor wires through the hinge passes. Restore the power bar cover.
4.Test your replacement repair by booting the laptop. If the screen looks normal, shut off the laptop and reattach the new screen to the base at the hinges. Restore the hinge covers.

I hope you find it very helpful. Thanks.