guys,., it is not even booting from bootable disk...

so either the boot sequence in mother board needs to be changed / fixed... it should be CD/DVD followed by HDD ... if ur hdd is before ur cd then it will always look for MBR (master boot record) in hdd,. and in ur case it is corrupt,.,. so change order,., insert bootable disk.,.,

if that doesnt work.,. check for virus in bios of ur mother board.. or as suggested earlier.,. diagnose for power supply failure...

hope it helps...