We’ve noticed a lot of people posting questions both in our support forums and in the Windows Vista newsgroups having issues getting bootsect.exe to do their bidding. Bootsect.exe is a command-line utility that ships on the Windows Vista DVD intended to repair a non-booting Windows Vista install – except it doesn’t always seem to work.
The problem that most people seem to be having can be traced back to single, simple fact: bootsect.exe does not modify the MBR: it only fixes/repairs the bootsector of your Windows Vista partition. The MBR is like a “global bootsector” that tells the BIOS where in the hard-drive it should look for a bootloader. The bootsector, on the other hand, is like a partition-dependant MBR – each operating system can have its own bootsector to tell your system how to boot it.
The source of all this confusion is that during the Longhorn/Vista beta program, quite a number of builds were shipped with a version of bootsect.exe (originally dubbed `fixntfs.exe`) that modified both the MBR and the bootsector.
However, in the Windows Vista RTM build and Longhorn Server builds following that, bootsect.exe is a command-line utility used to repair the bootsector and only the bootsector – it won’t get your MBR to use the Vista BCD/Bootmgr. In order to do that, you’ll have to boot from the Vista DVD | Repair Options | Command Prompt.
Bootrec.exe is an “all-in-one” boot-repair tool that can only be accessed and run from the Vista recovery console. The first command rebuilds the MBR to use the Vista boot manager. The second does the same thing as bootsect.exe and tells the bootsector where to find the BCD bootloader (\bootmgr). The final command rebuilds the BCD data from scratch and is highly useful when recovering a borked Vista partition.
EasyBCD also has options to perform each of these steps from within Windows. After installing EasyBCD, you can rewrite the MBR and the bootsector simultaneously by using the “Manage Bootloader | Reinstall Vista Bootloader” option. EasyBCD can also rebuild the BCD store and the entries in it (while EasyBCD is running from within both Windows Vista and other versions of Windows) from the “Diagnostics | Reset BCD Data” setting.
The moral of the story is simple: when attempting to use a utility, make sure to research the latest version before doing anything mission-critical. And the next time you’re developing an operating system and decide to switch the core functionality of a certain tool, be sure to document what you just did so this kind of thing doesn’t happen! =)