Windows 8 UEFI gone from bios boot options

Discussion in 'Windows 8' started by --__--, Oct 14, 2012.

  1. --__--

    --__-- MDL Novice

    Sep 17, 2009
    3
    0
    0
    Hello

    After i updated my BIOS, the entry for Win8 UEFI boot is gone (i think the nvram was cleared), i'm still able to boot it like a normal HDD, but i would like to readd it as an UEFI option.
    I did try to use windows build-in auto repair, but it didn't detect any problems...

    Does anyone know how to readd Windows 8 as a UEFI boot option?

    Thanks in advance
     
  2. Flipp3r

    Flipp3r MDL Expert

    Feb 11, 2009
    1,477
    629
    60
    Your install must of been in Bios mode. If it was EFI then it wouldn't boot. In EFI, the system files are in a EFi partition & no partition is labeled active.
    An active partition is needed for bios mode...
     
  3. --__--

    --__-- MDL Novice

    Sep 17, 2009
    3
    0
    0
    The board is a GA-Z77X-UD3H

    It says that the active partiton is a 350 MB system reserved, so that means it's installed in bios mode?

    Is that because i installed it from USB? Or maybe because its a RAID 0 setup?

    I just thought that if you had a UEFI boot option, this would be EFI mode And i had one of those but it disappered after a BIOS reset.
     
  4. Flipp3r

    Flipp3r MDL Expert

    Feb 11, 2009
    1,477
    629
    60
    350MB active is a typical bios/mbr install. GA, is that Gigabyte? Anyway, to install in UEFI, insert your usb key, boot the system, press your function key for boot menu (F12 I think).
    Your key should be listed twice, 1 for bios/mbr the other uefi, select uefi.
    at the 1st screen you can press SHIFT+F10 to go to command prompt. Run diskpart to wipe your disk & convert it to GPT. ie,
    sel dis 0
    cle
    con gpt
    exit diskpart, exit command prompt, continue install!

    Good luck!
     
  5. mengchanchai

    mengchanchai MDL Junior Member

    Nov 25, 2007
    91
    3
    0
    Dear Sir
    May I ask you a stupid question? :D
    What advantage to boot in UEFI option? :)
     
    Stop hovering to collapse... Click to collapse... Hover to expand... Click to expand...
  6. Flipp3r

    Flipp3r MDL Expert

    Feb 11, 2009
    1,477
    629
    60
    With UEFI you can boot from 3TB+ Hdd. Non-UEFI you will get max 2TB & the remainder is unused. Not sure what else. Same boot speed last I tested...

     
  7. --__--

    --__-- MDL Novice

    Sep 17, 2009
    3
    0
    0
    Thanks Flipp3r.

    I'll try it when Win8 is released, as i'm running the evalu right now, and i will have to reinstall anyway when it's released :)