17 May 2012

So I built a new PC this week!  I’ll post more about that later, for now I want to document how I got booting the Windows 7 install in UEFI working so that I can take advantage of my whole 3TB drive and not just 2TB of it!

The UEFI “BIOS” comes pre-config’d for UEFI so I didn’t think I needed to do anything.  I installed windows by all the defaults in the wizard.  Then I realized that 764GB of my drive was unallocated and it wouldn’t let me create a partition!  I know I had read that Windows 7 supported the larger drives so I hopped on the net to try and figure out what was going on.  Turns out you have to explicity boot UEFI so I hopped into the setup utility to configure that.  For those of you who had already installed Windows, there will be an extra few steps to convert the drive.

  1. Turn on the PC and plop in the Windows 7 CD (or wait until you restart after uefi changes)
  2. Press the [Del] key to enter setup
  3. The main screen, which is the EZ setup, should have your bootable devices listed along the bottom.  You drag and drop them to change the order.  The one you’re looking for will be an icon for a hard drive (looks like an iPod).  It should have UEFI P3 and ASUS in the name.  Mine was stated as being 44XXMB.  Not sure what it was reading as 4.5GB but ok..
    1. It should really be the only UEFI listed.  If you’re like me, however, you might have a USB stick plugged in you forgot about and it will recognize this as a UEFI bootable device!  It’s icon was represented as a CD drive (for removable media)
  4. After moving your UEFI to the front of the boot order, go ahead and exit (button in top right) and save and restart.
  5. It should automatically starting loading the Windows CD after POST.
  6. Once it’s up to the first screen we need to make sure the drive is set to GPT (otherwise Windows can only use the first 2 TBs).  To do that press [SHIFT] + F10 which will open a command prompt
  7. Type DISKPART and hit [Enter]
  8. Type list disk and hit [Enter]
  9. It should display a list of all of your drives.  At the end of the row for each drive is a GPT column and there should be a * in it.  If not we need to convert it.
    1. Type select disk # where # is the number of the drive in the list.  If you’re not sure what drive is the one you want to install on, check the amount of space or, go to step 12 to see more details about the drive before making a choice.  That screen may tell you what is installed on other drives, but I”m not sure since I didn’t have any others.
    2. Type convert gpt and hit [Enter]
      1. If you did like me and already installed on this drive (or this drive was previously used and has volumes on it) you want to clear those first.
        1. After selecting disk, type clean and hit [Enter] to remove any volumes on the drive.  Then go back and convert to gpt
  10. If the drive was already GPT then skip to the next step, if you had to convert, reboot the PC and it should boot UEFI and start setup again.
  11. Once it’s back up go through the steps.  I don’t recommend doing an upgrade, I would select Custom Install  and start clean.
  12. Once you get to the screen to select the drive you want to install on, you should see your drive in it’s full capacity.
  13. Click on the Advanced options
  14. We want to create a new partition so select the drive and click New
    1. If you see a warning about not being able to install to that drive just ignore it as long as you get past the next step and can click next.
  15. Windows will warn you about making additional partitions.  According to my citation below it’s normal, necessary, and don’t touch it!
    1. The ones you see should say (System), (MSR)), and (Primary) next to them.  If your last one does not say (Primary) and it’s just blank, then setup was NOT run with UEFI and it’s setting up the disk as MBR instead of GPT.  Follow the steps for converting again and then reboot.
    2. Once you’re up and running in windows you can make as many logical drives as you want, so I wouldn’t worry about partitioning further here.
  16. You want to make sure the disk labeled Primary is the one you have selected and then continue on.
  17. Then just go through with the installation.

I was getting frustrated after reading MS’s article about converting the drive.  No where in the ASUS manual (or that I could find online) talked about what explicitly to do to make sure you were booting UEFI.  Thankfully I found the sites below to make the rest of my process easier after figuring that stuff out.



3 Responses to “Booting UEFI w/ Asus P8Z77-V Deluxe”

  • Anon Emouse
    November 13th, 2012 at 4:13 am     

    I love you. Thank-you for this information, I would have have (??) torn my hair out by now if not for you. Why the $%%^^ do we have to perform this strange alchemy? Regardless, THANKS!

  • Bob D
    February 7th, 2013 at 12:56 pm     

    Thanks for posting the informatation. I’ve been struggling with a veyr similar situation. I’m using the ASUS P8Z77-M motherboard, but I think it’s pretty similar to yours. The biggest difference I think is that it’s an ATX form factor. Anyway, I can’t seem to get the system to recognize the hard drive as UEFI. I see the little UEFI blue stripe across the corner of my DVD Drive icon in the boot order, but not on the hard drive. I’ve done the diskpart clean and diskpart convert steps several times, but it keeps installing into BIOS mode with a 2TB limit on a 3 TB drive. I’ve forward flashed, backwards flashed, sideways flashed the BIOS, and just can’t seem to get the UEFI stipe banner accross the hard drive icon in the Boot Priority area of the BIOS utility. If you have any thoughts, please let me know! Thanks much.

  • thegeek
    February 7th, 2013 at 5:48 pm     

    Was this a new drive? If not I would boot with the Windows CD, do the Shift+F10 at the first screen to get the command prompt and then clean the entire disk (start DISKPART and use “select #” – where # is the disk number) and then use the “clean” command (there can’t be any volumes on it to convert it). Then use “convert gpt” to convert it. Use “list disk” again to make sure there is a * under the GPT column. If not, I would try reformatting the drive and starting the diskpart stuff over. After it’s converted you gotta reboot and go back into the configuration screen to see if it’s there. If after all that it still doesn’t work, maybe there’s a hardware issue somewhere. I’m assuming this is a SATA drive, right?

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