Press down the power button and hold it down, and then with the button pressed down, press F12, and hopefully the computer will boot normally.

Failing that:

Check the memory (accessed at back of machine). Try reseating the memory module, and make sure the contacts on the module are clean. Try moving it from one slot to another. If reseating will not help, find a known good memory stick and test the laptop again.

Try starting the laptop without the hard drive. Sometimes a failed hard drive can halt entire system.

Finally, minimize the laptop as much as you can. Check all connections. Remove all devices and leave only three main parts: motherboard, processor and memory.

Test the laptop with an external monitor. If you still experience the problem chances are you have a failed motherboard.

If you still have problems or you don’t feel yourself to be competent enough to do the above I’d suggest getting a repair shop to look at it.

Best of luck with it.

PLZ help me out????

1) Unplug the laptop.
2) Remove the battery.
3) Hold down the power button for about 30 seconds to 2 minutes.
4) Put the battery back in.
50 Boot up again.

I tried formatting it, thinking it maybe a virus issue, but to no consequence. In the midst of formatting, it got shut down again.

What should i do?

i have a lenovo n100 laptop. 80GB and 512 mb ram.