How do I install windows 7 as a dual boot alongside windows 10?

I have windows 10 installed on a UEFI system. I'm looking to install Windows 7 Pro 64 bit to have the option when I boot between Windows 7 and Windows 10. The problem I think is that it's a UEFI system. I've tried going into the BIOS and putting in into legacy support mode. I've got a USB with Win 7 on it, and a partition (on the hard drive windows 10 is installed onto) created for the install. When I boot into Win 7 setup it gets as far as selecting the drive to install to, but it won't let me install onto the set aside partition. It says "windows 7 cannot be installed the selected disk is of the GPT partition style". I tried googling the problem, but I honestly have no idea what I'm doing, and don't understand the possible solutions. Does anyone know how to help me? And if you do, can you put it in such a way that an idiot like me can understand?. Thanks.

necrofish666

Posted 2015-12-07T10:11:15.360

Reputation: 111

Answers

You either need to boot with the firmware in EFI mode and from a EFI compatible windows installation (e.g. a windows 7 x64 DVDROM or a pendrive with the correct files) and use a disk partitoned in GPT style,

You can boot from a BIOS or with the EFI firmware in legacy mode. In this case it will install on a disk which must be partitioned in the classic MBR style.

You cannot combine legacy mode and GPT.

The message windows 7 cannot be installed the selected disk is of the GPT partition style. seems to indicate that you are booting in legacy mode.

Hennes

Posted 2015-12-07T10:11:15.360

Reputation: 60 739

OK, so if I just turn off legacy support mode in the bios and boot as normal, selecting the USB as the boot device, I should be able to install 7 no problem? The install files are Win 7 Pro 64 bit, on a USB stick. – necrofish666 – 2015-12-07T10:54:22.973

Yes, though youi might need to point not at just the USB pendrive, but at the actual .efi file on that drive. – Hennes – 2015-12-07T11:05:28.247

Assuming you really only need windows 7 some times.

What about running windows 7 as a virtual install from within Windows 10, using the "Hyper-V" (which is free and built into windows 10).

admdvs

Posted 2015-12-07T10:11:15.360

Reputation: 21

Nothing wrong in the answer but it is not what OP is asking for. It must be a comment than an answer – pun – 2015-12-08T00:15:54.597

only answer I've seen that seems reliable is to by a 2nd hard drive, and install each to separate drives. a pain, yes, but the only option since windows won't install anywhere but the boot partition.

user531772

Posted 2015-12-07T10:11:15.360

Reputation: