Sightline is correct,...most of those models used a toshiba sata laptop disk drive,and they were notorious for failing,...go get a sata laptop drive and snap it in...as for the operating system ,An easy fix to not having a disk is to load the same version of windows listed on the genuine windows operating sticker on the bottom of the computer with the serial key listed ,...most of the c655 laptops use windows 7 home premium 64 bit for which you'll need a microsoft disk,...or upgrade disk to install it. These run $120 new so if you know anyone with a disk and or can borrow one I would advise it,...use the same serial key as on the decal on the bottom of the laptop and activate the windows 7 operating system,...then go to toshiba support site for that exact model and download all the drivers and utilities for that model and install them,..this should put the laptop in out of the box state,...have fun heheheheheheheh