try pressing f8 as you start laptop to start in safe mode,if successful pick last known good config.
also if you have any discs in drives - remove them also remove any usb items and try reboot.
if this is of no help try Pressing f2 whilst starting to access bios and make sure the boot order is cdrom then hard drive.
how long does cursor stay on screen does anything else happen?
have you installed anything software/hardware?
are you running vista