No Bootable Device Found--Insert Boot Disc and press any key. please help!!?

Last night, my mom and i went for a jog. I had been sitting at the kitchen table with my laptop working on a word document from my USB, not wanting to have to restart it completely i set it to hibernate, unplugged it and left it on my bed, when i came back about an hour or so later, i turned it on and it began to make this sound that i can only liken to techno music or disco maybe and it gave me the error "NO BOOTABLE DEVICE FOUND--INSERT BOOT DISC AND PRESS ANY KEY" I don't think it's my hard drive because I just got it replaced on WEDNESDAY...PLEASE HELP MEEE!!!!