Disk faulure insert boot cd

Hello,the post before this was beacuse of this problem:my windows cant start without boot cd and i try almost everything.First i was format windows and replace with another one then finding some viruses and remove them then checking for bad sectors on my hd and i want to try now to update the bios.Is this wisely or what should i do
When i start my pc is very slow and when it need to boot it say DISK FAULIRE PLEASE INSERT BOOT CD something like that PLEASE HELP ME and Thank you very much.