แก้ปัญหา OS Boot ไม่ขึ้น : BOOTMGR is missing in Windows Server 2008 R2

[admin]

what happen to me was I accidently marked one of my iScSi drives as active so the server failed to boot. What worked for me to fix it was:


1. ใส่แผ่นติดตั้ง OS เข้าไป -> Boot from your Windows Server 2008 R2 x64 DVD.
2. เข้าเมนู Repair
3. เลือก Command Prompt
4. ป้อนคำสั่ง rename c:\boot\BCD bcd.old
5. Bootrec /RebuildBcd
6. diskpart
7. select disk 0
8. select partition 1 (the 100MB partition)
9. active
10. exit
11. reboot server and remove DVD

Ref: https://social.technet.microsoft.com/Forums/office/en-US/0e6a7b6a-70de-41af-b2c8-5f8f3c86cef7/bootmgr-is-missing-in-windows-server-2008-r2

http://www.akcsys.org/master/index.php?topic=755.0