When you turn on the power of your computer, press del button on your keyboard, to see if you are able to enter BIOS setup, if you are then, just come out of it without making any changes in it.
Than keep on pressing F8 button on your keyboard, if you see a screen giving you different information, select "Safe Mode" and press enter button and see if you are able to boot into "Safe Mode".
If you are able to enter "Safe Mode" then it could be an issue with any of your hardware device.
Please inform us as soon as possible if you are not able to enter BIOS setup.