Overcoming "windows can only be installed to gpt disks" while installing windows 8 to new computer

As per technet.microsoft.com follow the below steps:

1. Turn off the PC, and put in the Windows installation DVD or USB key. Boot the PC to the DVD or USB key in UEFI mode. For more info, see Boot to UEFI

2. Mode or Legacy BIOS mode.

3. From inside Windows Setup, press Shift+F10 to open a command prompt window. Open the diskpart tool:

   diskpart
   

4. Identify the drive to reformat:

   list disk
   

5. Select the drive, and reformat it:

   select disk <disk number>
   clean
   convert gpt
   exit
   

6. Close the command prompt window. Continue the Windows Setup installation. When choosing an installation type, select Custom.

7. The drive will appear as a single area of unallocated space.

8. Select the unallocated space and click Next.

9. Windows begins the installation.

Inside windows installer, hit Shift+F10 to get a command prompt, then run diskpart and select the target disk. Zap the drive (with the clean command), create GPT table (new gpt), create the GPT-EFI special partitions.

Step-by-step instructions provided by Microsoft here (For Windows XP x64, newer versions of diskpart such as included in your Windows 8 support all these commands and more)

Then reboot so the firmware finds those partitions and adds the disk to the EFI-native boot order (Windows installer checks this).