I have a UEFI HP G7 Laptop with Windows 8.1 pre-installed, and I'd like to add Windows 7 as a dual-boot.

In Win8, I've turned off Fast Startup, made room on the existing partition in order to create a new NTFS logical partition along side.

The problem is when I select to install Windows 7 x64 from the DVD, it complains that the new partition is GPT! Shouldn't Win7 x64 be UEFI friendly and install on a GPT drive?

Note, in HP's BIOS/UEFI menu, I've disabled Secure Boot, however if I don't select "Legacy/CSM" support, then it won't even boot from the DVD. It only boots from the DVD if I select Legacy, but I think that is what is also preventing the installation to anything other than MBR.

How can I get around this?


2 Answers 2


Your DVD will not work here !!!

You have to create a bootable usb capable to booting into uefi.

Make sure that you have win7 iso file. If not, you have create it from your dvd.

Download and run Rufus. Make sure that partition scheme and target system type option is set to GPT partition scheme for UEFI. Then browse for win7 iso image and click start.

enter image description here

This will create a bootable usb capable to booting into uefi.

  • Thanks, even converting the ISO to a bootable usb using Rufus, Windows reports same GPT message when I try to install. Interestingly, I had to keep the 'Legacy' support set in the BIOS or else it would not recognize the USB. Seems like the ISO (an All-In-One Win 7 x32/x64) is not in the right format to be UEFI bootable, but not sure what to look for.
    – ben
    Commented May 13, 2016 at 16:05
  • Thanks, that worked! For whatever reson, I still had to set Legacy/CSM mode to not only install, but to actually use win7 and win8, but that's fine! Next up, trying to figure out WindSlic!
    – ben
    Commented May 16, 2016 at 6:32

Depending on where the ISO was obtained, it might not be properly created for UEFI booting. The file structure will be fine, including the \boot\efi directory, but the boot files will not properly load.

In addition, according to Microsoft, Windows 7 cannot be used without CSM being enabled. Windows 7 does not support UEFI Class 3 (pure EFI) due to a requirement of of BIOS INT10. Windows 8.x and 10 support UEFI Class 3. Source here

  • Like you said, the ISO has the boot\efi files, but isn't detected unless CSM is enabled, which then seems to prevent the installing on a GPT partition. Sounds like there's no official Windows7 UEFI version, but how then do people dual boot win7 and win8/10? Are they using a modified version of Win7?
    – ben
    Commented May 13, 2016 at 16:08
  • Windows 8.x and 10 can be installed in CSM mode. This allows for Windows 7 to be installed as well. You can also use logical partitions to have more than five active partitions, if that's the show-stopper.
    – Rikai
    Commented May 15, 2016 at 22:43

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