Cant find harddv new motherbd installed vista

Hello, Anyone I have installed new motherbd and CPU, eveerything went well. On startup
i get thru to vista install/repair screen. and the system will not start. checked bios it sees it, but when at vista it does not see it in windows. I was going to format the drive and start fresh and new with comp. might not need to. But i need to find hdrive. any help would be great