There are a number of possible causes for BOOTMGR errors, including the most common "BOOTMGR is missing" error message.
The most common reasons for BOOTMGR errors include corrupt and misconfigured files, hard drive and operating system upgrade issues, corrupt hard drive sectors an outdated BIOS and damaged or loose IDE cables
Anothe reason you might see BOOTMGR errors is if your PC is trying to boott from a hard drive or flash drive that is not properly configured to be booted from. In other words, it's trying to boot from a non-bootable source. This also would apply to media on an optical drive or floppy drive that you're trying to boot from. make sure there are no disks in cd floppy usb drives Test all power and data leads that attach to your hard drive ,SATA the leads from your ((MOTHERBOARD TO YOUR HARD DRIVE)) make sure they have a secure dust free connections and are not faulty or just replace them they could be faulty
Make sure all power and data leads that are attached to your drives dvd\cd have secure connections and are not faulty or just replace them they could be faulty a computer needs Data and Power to travel through every working device and to continue its cycle and to have an end so any faulty leads will end up with a computer error. also make sure you have set it boot from you hard drive in BIOS Restart your computer and enter BIOS mode. On most computers this is done by pressing the Delete ot F2 key but will vary depending on your computers bios other keys Acer: - Ctrl+Alt+Esc , ALR PC: (F2) or (Ctrl)(Alt)Esc) , Award BIOS: (Del) or (Ctrl)(Alt)(Esc).
Scroll over to the "Hard Drives" tab, and make sure your computer has the hard drive assigned to be on. Often during BIOS you can select auto-detect or change options with your hard drive to make sure Windows can recognize it. Once you've selected your desired options, continue to boot.
Restart your computer repeatedly tapping the f8 key to enter safe mode while the screen is black once in safe mode where the only things working will be your keyboard and mouse allowing you to attempt to repair your computer
As the computer is booting repeatadly press the F8 key as the computer is booting
If done properly the user should get to a screen similar to the below screen. Select the option for Safe mode command prompt only Windows Advanced Options Menu
Please select an option: Safe Mode
Safe Mode with Networking
Safe Mode with Command Prompt Enable Boot Logging
Enable VGA mode
Last Known Good Configuration (your most recent settings that worked)
Directory Services Restore Mode (Windows domain controllers only)
Debugging Mode Start Windows Normally
Return to OS Choices Menu Use the up and down arrow keys to move the highlight to your choice. select safe mode with command prompt Then type at the C:\> prompt: type
and hit Enter. You'll see a dash (-) at the DEBUG prompt. Now type:
o 70 2e
which will show as -o 70 2e at the DEBUG prompt. Hit Enter. Then type:
o 71 ff
and hit Enter. Finally type:
and hit Enter one last time to quit DEBUG back to the C:\> prompt.
Now you're ready to reboot your PC, and press the appropriate key or key
combo (look it up in your motherboard manual if you don't know it) to access
your BIOS Setup. Youll notice the password is gone. If this fails try typing At command prompt type debug you will get a - prompt where you can type the following (<enter> means press enter, not type enter*)
MOV AX,0 <ENTER>
MOV AX,CX <ENTER>
OUT 70,AL <ENTER>
MOV AX,0 <ENTER>
OUT 71,AL <ENTER>
INC CX <ENTER>
CMP CX,100 <ENTER>
JB 103 <ENTER>
INT 20 <ENTER>
<ENTER> just hit enter on this line
Basic BIOS password - works 9.9 times out of ten
If this fails you will need to Select safe mode with networking to download you could download all of these or just one save them to a usb drive for later use if one fails to remove the password http://www.tech-faq.com/reset-bios-password.html
At some stage you might need to press Ctrl+Enter rather than just Enter if on a Dell Latitude E5410 http://majorgeeks.com/CmosPwd_d239.html
A CMOS BIOS password recovery tool Editors note: This tool should only be used by experienced computer users. Please see the enclosed read me if you would like to run it from Windows. Failure to follow instructions (from Windows) will cause your anti-virus to flag this as a virus. Hope this helps.