Being unwilling to use Ubuntu any more, I deleted the partition that contains the system, but it deleted GRUB at the same time, and now my computer cannot boot into Windows 8. I looked online and was suggested to fix MBR with Windows 8 disc. Nevertheless, I do not have such a disc. What should I do?
MBR (Master Boot Record) is the boot sector in the front section of the driver, which contains the partition table for the drive as well as executable code for the boot start. MBR is formed when the first partition of a hard drive is created. Once MBR is corrupted, your computer will fail to boot, and the error “Operating System not found” or “Missing operating system” will show up. Generally speaking, MBR corruption issue is caused by malware infection, or improper shutdown. In such case you should find a way to repair MBR to fix the issue.
If you have a installation disc, you can fix MBR in Windows10 by input some command prompt. Or you can connect your disk that need to be fixed into another machine so as to make the fix job easier. Also, a bootable partition manager is a good choice.
Solution 1: Use command prompt to fix MBR in Windows10
1. Boot into System Recovery Options and run “Command prompt”, then type bootrec.exe and press Enter to see the options that are available for this tool. (usually they are: /FixMbr, /FixBoot, /ScanOs and /RebuildBcd.)
2. Execute /FixMbr in Command Prompt.
Solution 2: Connect hard drive to another PC to Rebuild MBR
1. Connect the hard drive with corrupted MBR to another normal computer.
2. On the normal computer, download, install and launch MiniTool Partition Wizard Free Edition. Then select the newly connected disk and right-click it to choose “Rebuild MBR”.
3. Click “Apply” to finish this operation.
Solution 3: Rebuild MBR in Windows under boot mode
1. On a normal computer, download MiniTool Partition Wizard Bootable CD and burn it to a USB flash drive. (How to Build Free Bootable Partition Manager with Pwfree91.iso?)
2. In BIOS, set you machine to boot from this USB flash drive.
3. Click on the system disk and choose “Rebuild MBR”.
4. Click “Apply” to finish this operation.
Note: “Rebuild MBR” would not lead to any kind of data loss. However, improperly operations on repairing MBR might cause more serious issue. Thus, you’d better learn more before you execute “Rebuild MBR”.