Windows 7 How to add a boot manager/bootloader to a Win7 HDD

1. Create a Windows 7 System Repair Disc. You can create this from another computer with the same architecture (32-bit or 64-bit) running Windows 7. To create the disc, go to Control Panel > System Maintenance > Backup and Restore, and click on Create a System Repair Disc on the left sidebar.
2. Modify BIOS Settings. Start your computer and press the key to get into the BIOS settings. It is usually F2, F10, DEL, or ESC. In the BIOS, set the boot priority to first boot from CD/DVD or USB (depending on where your repair disc is). Save settings and restart your computer.
3. Boot windows via the Repair Disc. Insert the repair disc to your CD/DVD or USB drive then restart the PC. Since BIOS is set to boot from CD/DVD or USB, it should start from the repair disc.
4. Go to System Recovery When the system recovery option window appears, choose "Command Prompt".
5. Use Bootrec.exe Tool. In the command prompt, type the command "bootrec.exe" then press Enter. This tool will fix the Windows 7 bootloader. Here are the commands to be used for the bootrec.exe tool:
   • bootrec.exe /fixmbr - this option writes an MBR (not bootloader) to the system partition. It does not overwrite the existing partition table.
   • bootrec.exe /fixboot - this option writes a new boot sector onto the system partition using the boot sector compatible for Windows.
   • bootrec.exe /scanos - this option will scan all disks for installations compatible with Windows and display them, helpful if Windows cannot find any systems.
   • bootrec.exe /rebuildbcd - this option can be used if the boot configuration data store is corrupt or missing. It scans all disks for installations that are compatible with Windows. Additionally, this option lets you select the installations that you want to add to the BCD (Boot Configuration Data). After using the tool you can restart the computer and hopefully, the Windows 7 should boot normally. Remember to backup any important files before you do this, to avoid losing your data if anything goes wrong. If you're not comfortable doing this by yourself, it might be a better option to get professional help.

How to Use the Windows 7 Installation Disc to Repair the Bootloader:​

1. Boot from the Disc:
   • Insert the Windows 7 installation disc into your drive.
   • Restart your computer and boot from the disc (you may need to press a specific key like F12 or Esc during boot to access the boot menu).
2. Access System Recovery Options:
   • When the installation menu appears, select your language preferences and click Next.
   • Look for the option "Repair your computer" and click on it.
3. Select the Windows Installation:
   • The system will scan for installed Windows versions. Select your existing Windows 7 installation and click Next.
4. Use Built-In Repair Tools:
   • In the System Recovery Options menu, you have two relevant options:
     • Startup Repair: This will automatically attempt to fix problems with the bootloader/boot manager.
     • Command Prompt: If Startup Repair does not work, use the following commands in Command Prompt to rebuild the bootloader manually.

Manual Repair Commands via Command Prompt:​

1. Run the following commands one at a time:
   
   Code:

   cmd
   bootrec /fixmbr
   bootrec /fixboot
   bootrec /scanos
   bootrec /rebuildbcd

   • /fixmbr: Writes a new Master Boot Record to the system partition.
   • /fixboot: Writes a new boot sector.
   • /scanos: Scans for installed Windows operating systems.
   • /rebuildbcd: Rebuilds the Boot Configuration Data (BCD).
2. Restart your computer after executing the commands.

Alternate Path:​