Firstly, booting from the cd will tell you if the pc is still bootable!! Emachine psu's (power supply unit) are notoriously crap, they have a habit of going bad and killing the mobo!! If it will boot from the cd that will at least tell you that the mobo is still working!!!!
Secondly, the cd will not necessarily wipe the hard drive!! It may be possible for it to recover windows for you without a reinstall!!!!