BootMGR, the short name of Boot Manager, is a small program that allows multiple operating systems to be booted from the same computer. It's also called a boot loader. So if this BootMGR file is missing or compressed, you can't start your computer normally. What error messages that users usually get about BootMGR:
• BootMGR is missing, please press Ctrl + Alt + Del to restart
• BootMGR is compressed, please press Ctrl + Alt + Del to restart
What you need: Windows Vista or Windows 7 disk
1. Insert your Windows Vista or Windows 7 disk into the DVD player and restart the computer.
2. You'll see the boxes of Language, Time and Currency and Keyboard in the next screen.
3. There are two options on the lower left side. One is "Repair your computer", and the other one is "What to know before installing Windows".
4. Click on the first one: "Repair your computer".
5. Windows will then try to find the installation directory for Vista or Windows 7, depending on what you have.
6. Next up is a screen with a box called Recovery Options. Click the first option, Startup Repair.
You'll see a Startup Repair box with the message "Startup Repair is checking your system for problems…".
7. When it's done, it will prompt you to reboot. If there is more than one problem it may reboot again to continue repairing.
8. At this time, you can plug out the DVD, restart your computer and everything should be working normally.
What you need: a system booting program
1. Get a related booting program, which should be a CD, DVD, or USB drive (you can't start the computer, so the program installed on your computer does less help). Here recommend Wondershare LiveBoot, which can help to automatically repair the booting failure Windows caused by the missing or corrupted BootMGR. It supports booting from CD, DVD, and USB drive.
2. Insert the CD into the CD-ROM of your computer, and start your computer.
3. Choose "Boot from LiveBoot" from the Boot Menu to start your computer. Then Windows begins to load files, which takes a few minutes.
4. When the file loading is finished, Windows starts, and then the LiveBoot menu comes up.
5. Then click the "Windows Recovery" tab and hit "Boot Files Recovery".
6. According to the instruction on the interface of "Boot Files Recovery", choose the target Windows and begin to scan. If there is only one Windows, you can skip this step.
7. The scan result will reports that the file is missing or corrupted, then start "Recover" to get your Windows back.
8. Then you only need to get the disk off your computer and restart the computer, and the system returns to good now.
By the way, you can also know more fixes on BootMGR missing issue.
As the above shows, we provide a few efficient ways to help you fix the BootMGR Missing issue. In most cases, you will boot the computer after applying the above solutions. However, once you fail, you have to resort to Recoverit Data Recovery software to retrieve data from the unbootable computer. Just follow the below steps to make it.
1. Once you have downloaded and installed Recoverit, you need to move the mouse cursor towards the data recovery mode. If your Windows 10 is unable to reboot, you need to tap on the ‘Recover from Crash Computer mode’; next, a new pop-up window will open after you tap on the corresponding ‘Start’ button.
2. Once here, you need to choose the model that will allow you to create a bootable drive; you can then either choose a CD/DVD bootable drive or USB bootable drive. To start, you need to tap on the ‘Create’ button.
3. In the following pop-up window, your system will request a full-format of the USB drive. Also, you need to back your important data. Once done, tap on the ‘Format’ button to start the process.
4. On tapping the ‘Format’ button, the program will start creating a bootable drive. You need to ensure that you do not remove the USB flash drive. The program will show you all the steps on what to do next from here; alternatively, you can also take a look at the entire data recovery guide.
5. Creating a bootable drive can take some time. Here, you just need to follow three simple steps for data recovery.
6. Change your computer boot sequence and set the boot from the newly-created bootable media; this needs to be done before you start recovering your data from your unbootable Windows 10.
Once done, you need to restart your system and tap on the F12 function key to enter the BIOS. Different systems will have different BIOS entry key. You can know more about it here.
7. The Recoverit program will launch automatically after booting from the bootable drive. All you need to do now is recover or copy all your files from Windows 10. With the help of this process, you will be able to recover your precious data from your unbootable Windows 10 computer. With the help of Recoverit, issues regarding data loss are fixed on your Windows 10 system.