Only use those commands in the VRE. They're part of the VRE, and not Bartpe or UBCD, so you couldn't use bootrec there even if you wanted to.
I should have specified that when you get to the D: command prompt, type c: and enter to get to the C: drive, then run those two commands:
Make sure you're at the c: prompt.
bootrec /fixmbr
bootrec /fixboot
EDIT: I found this on another tech website. I will assume for this that you have just booted with the DVD and have started the VRE: Try the following commands:
copy c:\boot\bcd c:\boot\bcd_backup <hit enter>
c: <hit enter>
d:\boot\bootsect.exe -NT60 SYS c: /force <hit enter>
Reboot to the Vista Boot DVD again.
Click on the startup recovery option at the top.
Reboot.
I should have specified that when you get to the D: command prompt, type c: and enter to get to the C: drive, then run those two commands:
Make sure you're at the c: prompt.
bootrec /fixmbr
bootrec /fixboot
EDIT: I found this on another tech website. I will assume for this that you have just booted with the DVD and have started the VRE: Try the following commands:
copy c:\boot\bcd c:\boot\bcd_backup <hit enter>
c: <hit enter>
d:\boot\bootsect.exe -NT60 SYS c: /force <hit enter>
Reboot to the Vista Boot DVD again.
Click on the startup recovery option at the top.
Reboot.