How to Remove Android-x86 and GRUB Loader

First boot into Windows, go to C: and delete android-xxx and grub folder. Then, you need Windows Installation disc or Windows bootable USB flash drive to restore Windows bootloader.

1. Insert Windows Installation disc or Windows bootable USB flash drive.
2. Boot the target drive by changing the boot order in BIOS.
3. Select a Language, Time and currency format, and keyboard or input method.
4. Click Repair your computer.
5. Select the operating system to repair and click Next.
6. In system recovery options dialog box, click Command Prompt.
7. Type Bootrec.exe /FixMbr and hit Enter.
8. Reboot your computer
   Don't forget to change hard disk back to boot first in BIOS.

If you don't have Windows Installation disc or Windows ISO file, you can use EasyBCD to install Windows bootloader to MBR. This software is easier to use but it's better to use official installation disc to recover Windows bootloader.