Windows Vista includes a new Boot Manager (BootMgr) that replaces the old NT Loader (Ntldr).

If the boot partition no longer can be found, then Vista will display the following error:

BOOTMGR is missing. Press Ctrl+Alt+Del to restart

The Windows Boot Configuration Data file is missing required information

More Info MS KB 919529
More Info MS KB 927391

This can usually be solved by checking the boot devices, and if no problems found then use Windows Recovery Environment (WinRE) and perform a “Startup Repair”.

If by accident having compressed the entire boot partition, then Vista will display the following error:

BOOTMGR is compressed. Press Ctrl+Alt+Del to restart

This can usually be solved by using Windows Recovery Environment (WinRE) and perform a “Startup Repair”. If that fails then use WinRE to enter the “Command Prompt” and execute these commands:

* compact /U C:bootmgr
* compact /U C:ntldr

Heres more information about t

Windows Vista introduces the Windows Recovery Environment (Windows RE or WinRE), which completely replaces the Recovery Console. WinRE is actually a Windows Preinstallation Environment (Windows PE), which enables much more advanced tools for system diagnosis and recovery.

To access the WinRE using the Vista install disk:

1. Boot from the Vista install disk
2. Choose your language settings and click “Next”
3. On the bottom of the screen click the link “Repair Your Computer”
4. Select the Vista installation to repair and click “Next” and it will launch WinRE

The following options are available in WinRE:

* Startup Repair – It will repair the boot manager files and restore critical files required for booting Windows Vista.

After attempting to repair the system it will display a Startup Repair diagnosis and repair log with the different Test Performed and the probably root cause.
* System Restore – Windows Vista automatically performs daily backups of system critical files and also before installation of drivers and applications. These backups are called system restore points, and this option makes it possible to restore the system state before the moment it started to fail.
* Windows Complete PC Restore – If having performed a backup of the entire system, then this option can be used to restore that backup.
* Windows Memory Diagnostic Tool – Memory modules can be sensitive to things like working with other memory modules, system-bus frequencies, motherboard models, overclocking etc. When the memory modules fails to work properly then the computer will become unstable especially when under load. More Info Windows Help
o If wanting to access the Memory Diagnostic Tool without installing Vista first, then boot from the Vista Install Disk, and when it says “Press any key to boot from CD or DVD…” hold down the Space-bar or press it multiple times. This should bring up the Windows boot manager, which has “Windows Memory Diagnostic” as an option.
* Command Prompt – Pretty much the same as the Recovery Console. Among other things it gives access to the boot manager configuration. More Info MS KB 927392:
o Bootrec.exe /FixMbr – Rewrites the Master Boot Record (MBR) for the boot partition.
o Bootrec.exe /FixBoot – Rewrites the boot sector for the boot partition.
o Bootrec.exe /ScanOs – Scans all disk for bootable partitions and displays the entries not in the BCD store.
o Bootrec.exe /RebuildBcd – Scans all disk for bootable partitions and allows one to decide what entries to rebuild the BCD store from (Similar to Bootcfg /rebuild in XP).
o BCDEdit.exe – Can backup / restore the Boot Configuration Data (BCD) store. Can change the boot manager options for a certain entry in the BCD.
Note the old Recovery Console commands to work with services and drivers (LISTSVC, ENABLE, DISABLE) are no longer available, but instead one can use regedit to edit registry hive offline and change the startup setting for the service or driver.

Note if not having the Vista install disc then the system builder might have created a hidden partition for the Windows Recovery Environment (WinRE). If this is the case then WinRE should be available when pressing the F8 key during startup (Like if booting into safemode). More Info How to install WinRE locally.

UPDATE: IF ALL FAILS DOWNLOAD A FREE COPY OF WINDOWS PE OR GET A FLOPPY DISK WITH WINDOWS DOS START UP AND IN THE COMMAND LIKES JUST TYPE
“BOOTREC/FIXBOOT” AND “BOOTREC/FIXMBR” AND BOOM THATS DONE.

I found this one out while trying to fix this one,so now im good. 😀 it works fine.