NTLDR Missing


I had a pre installed vista vaio laptop. I converter it to dual boot system with windows XP installed on it. I didnt get any back up cd with the laptop but it has a separate partition for recovery which used to come up when i pressed F10 during system boot. Now when i converted it to dual boot and now when I am pressing F10 to restore factory settings its saying NTLDR missing. Since I needed to format, I just formatted the partition of XP and again tried to reboot. But again its saying the same when pressing F10. Although I am able to boot Vista normally

Its just that I am not able to get to the system recovery.

Thanks in Advance
My problem is not the dual boot. I have uninstalled XP and want to run system recovery by pressing F10 when system boots. I have a sony vaio SZ series laptop.
If Sony documents F10 as the hotkey to boot your recovery partiton and you cannot boot it, it means it has been messed up (Either MBR or partition related). Not much we can do if that is the case. Contact Sony for a recovery/OS disc if they did not provide you with one.