Solved BOOTMGR is missing error in Windows 7 Professional SP1 x64 OS on Dell Precision T7600 workstation (Rev: 1.0)

The Dell Precision T7600 workstation came with a Dell Recovery Partition (about 11 GB) in the Windows 7 Professional SP1 x64 Operating System (OS). As I will perform an OS backup after I have updated the Windows 7 OS and software with the latest patches, I wanted to delete the Dell Recovery Partition to recover the 11 GB hardisk space.

I booted up from an Acronis Disk Director (ADD) 11 Home edition bootup CDROM. Then, I used the ADD 11 Home software to delete the Dell Recovery Partition and resized the Windows 7 Professional SP1 x64 OS partition to take over the deleted Dell Recovery Partition size. If we did not set the Windows 7 Professional SP1 x64 OS partition as a boot (active) partition, an "Operating system not found" error will appear if we reboot the Dell Precision T7600 workstation. Hence, to prevent the "Operating system not found" error, I set the Windows 7 Professional SP1 x64 OS partition as a boot (active) partition and reboot the workstation.

After rebooting the Dell Precision T7600 workstation, the "BOOTMGR is missing. Press Ctrl+Alt+Del to restart" error appeared. If you boot the Dell Precision T7600 workstation from a Windows 7 x64 System Repair Disc (created from Windows 7 "Control Panel" -> "Backup and Restore" -> “Create a system repair disc”), load the Dell PERC H310 adapter version "A00 5.1.112.64" (download from Dell PERC H310 Adapter website) drivers from an USB thumbdrive, the Windows 7 x64 System Repair will still not be able to see the Windows 7 Professional SP1 x64 OS.

Hence, all those Automatically Startup Repaired that tried to solve the computer's startup options will fail to solve the "BOOTMGR is missing. Press Ctrl+Alt+Del to restart" error. When we view the problem details, it will indicate Problem Signature at 03, 05 and 07 as unknown. If we open the command prompt and try using the below bootrec.exe commands, it will also not work:

# bootrec /fixmbr
The system cannot find the path specified.

# bootrec /fixboot
The system cannot find the path specified.

# bootrec /scanos
Total identified windows installation: 0


Steps to solve the "BOOTMGR is missing. Press Ctrl+Alt+Del to restart" error

1. Power off the Dell Precision T7600 workstation. Kindly open the front cover (assume it is not locked from inside) of the Dell Precision T7600 workstation and pull out the Windows 7 bootup SATA3 hardisk at slot 0.
   
   
2. I have a Dell Dimension 5150 computer which has a SATA connection. With the Dell Dimension 5150 computer in power off stage, I took out the original hardisk from the Dell Dimension 5150 computer, and connect the hardisk from the Dell Precision T7600 workstation to the Dell Dimension 5150 computer SATA connection.
   
   
3. After power on the Dell Dimension 5150 computer, I immediately press F12 (device boot up options for Dell Dimension 5150. Please check your computer manual for the correct bootup key to press for your computer). This will allow me to choose to boot from CD/DVD drive so that it will boot up the Dell Dimension 5150 computer from the Windows 7 x64 System Repair Disc. At the System Recovery Options, a prompt automatically appeared with the below message:
   
   Windows found problems with your computer's startup options. Do you want to apply repairs and restart your computer ?
   
   I clicked the "Repair and restart" button and the Dell Dimension 5150 computer rebooted.
   
   
4. Once the computer has rebooted, I repeated step 3 to boot the Dell Dimension 5150 computer from the Windows 7 x64 System Repair Disc again. At the "System Recovery Options" stage, I clicked to select the "Windows 7 Professional (recovered)" and click the "Next" button. When the automatically "Startup Repair" stage had completed, another message appeared:
   
   Restart your computer to complete the repairs.

I clicked the "Finished" button and immediately power off the Dell Dimension 5150 computer so that it will not reboot. With the Dell Dimension 5150 computer power in off stage, I took out the hardisk (previously taken out from the Dell Precision T7600 workstation) and install the hardisk back to the Dell Precision T7600 workstation at hardisk slot 0. This time, the Dell Precision T7600 workstation had successfully boot into the Windows 7 Professional SP1 x64 OS. The "BOOTMGR is missing" error was solved.