Just as a follow up to this, if you need to convert during the Windows installation, please follow the below steps, again this process will wipe the hard disk specified;
- Start the Windows installer by booting from the Windows media.
- Open an elevated command prompt by pressing SHIFT and F10 together on the keyboard at the "Install Now" screen of the Windows installation
- In the command prompt. type diskpart and press enter.
- At the DISKPART prompt, type list disk and press enter - make note of the disk number you want to perform this action on.
- At the DISKPART prompt, type select disk 1 (where disk 1 is the number from step 4) and press enter
- At the DISKPART prompt, type clean and press enter
- At the DISKPART prompt, type convert gpt or convert mbr as appropriate, and press enter.
- Now close the command prompt window and follow through the rest of the installation process.