Start up computer (laptop Dell latitude D600)

Check your warranty, if it's under warranty, call your manufacturer or where you bought it. Blinking cursor means there is a problem with the operating system (windows) or the hard drive itself. It might need to be replaced or reformatted. Try putting in your operating system CD (CD given by Dell with the laptop) inside and restart the PC. If it asks you to press any key to boot from CD, you press any key immediately. If you missed it, then restart one more time. If it still doesn't work I suggest you call your manufacturer.

your computer may be infected...if your computer new and no issues and you wee on the net searching you may got a visitor so go back to safe mode by clicking F8 upon starting and restor to the last poinjt that the computer was working good