My N4510 laptop will not boot, only showes the Dell logo and two options F2 and F12; after a few seconds will show a black screen with info about Intel corp and some patents and the message:

Realtek PCIe FE family controller series v1.19 (08/10/09)

PXE - E61: Media test failure, check cable

PXE - M0F: Exiiting  PXE ROM

Reboot and select proper Boot divice or insert Boot media

It was working normal in the last few days and no sign of issues or anything

What can I do ? And what do you think the problem could be ?  Pelase advice asap, all of my files from work are in my laptop and I have no back up.

Thanks for your help