HOW CAN I INSTALL A WINDOWS OS ON A GPT PARTITION

My internal HDD is 3 TB. Since MBR allows a maximum of 4 partitions I only made 3 partitions. But there is another restriction. Total disk size cannot exceed 2 TB. Using GPT gives boot problems and also said it is not a genuine windows copy. So I tried to reinstall the OS with my installation disk but windows said it cannot install itself on a GPT partition. That is why, I believe, the moment I switched from MBR to GPT, windows decided it was not a genuine version.

Fact is I have about 800 MB, unallocated in MBR, which physically exist but I can't use. How can I fix that?

Would Win10 have the same problem?

http://speccy.piriform.com/results/MndXGywXOYDeLclatNdEf1U 

Thank you very much for any help I might receive as well as for all the other useful suggestions received in the past for other issues.

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Is the copy of Windows geniuine?  Installing Windows 7 on a GPT partition can be done however not recommended/worth the hassle in my opinion.  A legal version of Windows 10 will be able to install on a GPT partition. 

http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_install/how-to-clean-install-windows-7-professional-64-bit/c052117c-8faa-4b5b-bd31-30bb9b21a0eb?auth=1

Other Google Links On Same

Louis

The Windows copy is genuine. I partitioned the disk in GPT. When I got to the part on which partition I would install the OS I got a message saying OS could not be installed on a GPT partition.

Thank you for the links hamluis.

KingDavidIII

I can download and install Win10 anytime. I have the Win10 icon on the taskbar. After installing Win10, can I change from MBR to GPT and recover the lost space?

Your Speccy link does not work.

What is the make and model of this computer.

Did you partition the for the UEFI GPT?

http://speccy.piriform.com/results/62Dfd0GZpj16rh3JxhGVbFo

The computer is home made. No make or model.

This is the M/B  http://www.gigabyte.com/products/product-page.aspx?pid=4492#ov

I bought a 3 TB internal HDD because the old one was full of unrepairable bad sectors (used HDD Regenerator)

I was not aware that it could not be partitioned fully as MBR, so about 800 MB of space became unusable. With Aomei Partition Assistant I changed the MBR system to GPT.

But when loading the OS again for a clean install, a message said I could not install the OS in any partition since they were GPT.

No wonder the HDD was so cheap.

From  https://msdn.microsoft.com/en-us/library/windows/hardware/dn640535(v=vs.85).aspx#gpt_faq_win7_boot

Yes, all versions can use GPT partitioned disks for data. Booting is only supported for 64-bit editions on UEFI-based systems.

What am I doing wrong? Is my system not UEFI-based? Should I tweak the BIOS somewhere?

Does the computer have UEFI. Windows 7 will not boot a GPT disk using a Legacy BIOS. You need a UEFI computer in order for Windows 7 to boot from GPT.

https://wiki.archlinux.org/index.php/Dual_boot_with_Windows

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  Windows Vista (SP1 and above, not RTM) and Windows 7 x86_64 versions support booting in x86_64 UEFI mode from GPT disk only, OR in BIOS mode from MBR/msdos disk only. They do not support IA32 (x86 32-bit) UEFI boot from GPT/MBR disk, x86_64 UEFI boot from MBR/msdos disk, or BIOS boot from GPT disk.

   

   

   

Your motherboard has UEFI firmware.  Follow John_21's advice and do a fresh install.

Make sure your MB has UEFI enabled and not Legacy Boot. Boot the install disk and when you get to the first install Screen press Shift + F10 which will bring up a command prompt window. Type the following but first detach any of your USB hard drives.

diskpart           Will open the diskpart command window

list disk

select disk X    where X is the number associated with your install disk. If you have only one internal drive it will be disk 0

clean               This will delete any partitions on the drive

convert gpt

exit

Exit out of the command prompt window and continue the install.

Thank you very much.

I am currently backupping heavy stuff to an external HDD connected via USB.

As soon as the backup is finished I'll detach the external HDD from the USB port and follow your advice

Edited by passacaglia, 22 December 2015 - 05:57 PM.