Recovering the Windows Bootloader
You installed a new copy of Linux and now you have the Grub bootloader instead of the Windows bootloader. Recovering the Windows bootloader for XP / Vista / 7 / 8.x can sometimes be easy and it can also be difficult.
This article assumes that you can still boot into Windows, just through the Grub boot menu. If you can’t boot into Windows then please go here and read this article from Windows. So now boot into Windows.
This is one method out of many, however I will try to make this as painless as possible.
Next you will need to download the EasyBCD program from here.
After you give your name and email address for non-commercial use, click on the Download button and save the file.
Now install the program then open it.
1: Next go to the tab that says: BCD Deployment, where going to be Reinstalling the Bootloader to the MBR and Bootsector.
In the drop down box that says Partition make sure you select the NTFS partition that’s around 300 MB. If there is no partition around that size then pick the bigger NTFS partition. Should be 50 GB to 1 terabyte or bigger. This should be the NTFS partition your Windows system is installed on.
Now under MBR Configuration Options you select Install the Vista/7 Bootloader to the MBR then click on Write MBR tab. What for it to finish then reboot your machine and see if you get the Windows bootloader. Hopefully everything worked.
2: If that did not work for you then we are going to reset the Bootloader Configuration.
Re-open the EasyBCD program and click on the tab that says BCD Backup/Repair.
Select Reset BCD Configuration option then Perform Action to begin recovery. Pick the letter of your Windows drive, then hit OK to continue. The drive letter is normally C:
What for it to finish then reboot your machine and see if you get the Windows bootloader. Hopefully everything worked.
3: If that did not work for you then we are going to re-create all bootloader files and settings all over again for Windows.
Re-open the EasyBCD program and click on the tab that says BCD Backup/Repair. Click on Re-create/repair boot files. What for it to finish then reboot your machine and see if you get the Windows bootloader. Hopefully everything worked.
If EasyBCD fails, that means a process has locked your BOOT folder. Manually delete this folder while booted into your Linux OS and delete the C:/BOOT folder, then try step 3 again. Just be carefull and I hope you made a backup before you started all this.
If you have any questions, please post a comment and I will try to help you.