Windows – Can’t intall Win 7 64Bit. Something about GPT disk

gptinstallationwindowswindows 7

I've got Asrock Z68 Extreme 3 Gen 3 with 2600k. It got the UEFI bios. I got 4 HDDs and I run them as AHCI setup.

Now, I want to install Win7 64Bit over my Win7 32Bit. I boot up from the DVD, all goes well until the menu where I have to choose the HDD I want to install Win7 64Bit on.

I choose c: like always and it tells me

Windows cannot be installed to this disk. The selected Disk has an MBR
partition table. On EFI systems, Windows can only be installed to GPT

What do I do now? I'm currently in Win7 32bit writing this, and this is how my partitions look like from win7 partition manager: enter image description here

Best Answer

You need to convert from MBR to GPT. TechNet has an article, Change a master boot record disk into a GUID partition table disk, with all of the details.