boot manager missing error cant find os when doing system restore



I'm having trouble trying to fix the error message boot manager is missing. I have downloaded and written to disc the recovery cd data for windows vista and have set it up to boot from cd drive which it does fine. However when I go to select an os on the system recovery options nothing comes up? Any idea how I can fix this thanks for any response
Disconnect any other HDDs while you try the repair.
If you still can't see the OS, click "next" anyway.
That will sometimes do the first repair successfully, at which point the OS should reappear, and you can go on to repeat the repair another two times to fix other broken parts of the boot.
Hi that didn't work it came up with a system error when it tried to do a repair any idea what else i can try?
Again thanks for any response
Boot the CD again and you have 2 other options from the "repair" screen, system restore and command prompt.
See if you can find a restore point from just before you had the problem.
Failing that, from the command prompt, run a chkdsk /r against your OS partition (it'll take a while), then try the repair again.