cannot load the hive (file)

Hi,
I have laptop running vista 32bit & yesterday it displayed blue screen on startup.
Cannot load hive, systemroot\system32\config\software.
I have the original vista disc to proceed with repair but the trouble i am having is once i insert disc to drive & then switch on laptop it does not start the cd.
I have changed the boot order in BIOS & also tried the cd drive in a different pc & checked the disc to see if that works correctly.
Any help & advise would be greatly appreciated.

Oh & i am not tooooo great with the computer language, i'm just a medioka nooob to this so take me easy.
Regards
Richard Ivory