If the boot sector of the system partition is broken,

The boot sector is destroyed, and the system will not start properly. In Windows 2000/XP, you need to enter the recovery console, and use fixmbr (fix the master boot record). Or the fixboot (fix boot sector) command.
Under Windows Vista, the same method is used to let the system automatically detect the startup failure, and Windows Vista can live up to the expectations, and it is easy to find the crux of the problem and automatically use the BCDMD command to fix it.
If there is no system startup failure, just want to test Windows Vista's "intelligence", then Windows Vista will politely and firmly say that the startup fix can't detect the problem.
From the performance of the startup recovery feature, Windows Vista is undoubtedly reassuring. It is commendable that the system does not require us to have the ability to judge faults, but to give all the work to Windows Vista to do it, which should be affirmed.