Convert GPT to MBR using Disk Management

1. Boot into your Windows (Vista, 7 or 8)
2. Click Start
3. Go to Control Panel
4. Click Administrative Tools
5. Click Computer Management
6. On the left menu, click Storage > Disk Management
7. Right-click on each partition from the disk you want to convert from GPT. You must delete all partitions from the disk before you begin the converting process from GPT. To do so, click Delete Volume on each partition until the entire disk has unallocated space.
8. Right-click on the disk and click Convert to MBR Disk
9. Once the process is done, you can now create partitions on the new disk as you wish
10. Close Disk Management when done.

Convert GPT to MBR using Command Prompt

If you’re not able to boot into Windows (Vista, 7 or 8) to run Disk Management and perform the converting process, you can also use Command Prompt (either from the original installation disc/USB or via Command Prompt from Easy Recovery Essentials).

You can perform these steps either by booting into Windows and running Command Prompt from Start > Run > cmd or by using the original installation disc to open Command Prompt, if you can’t access Windows.

1. Insert the Windows installation disc and restart your computer
2. Boot from the disc by pressing any key at the “Press any key” screen
3. Go to System Recovery Options
4. Click Command Prompt
5. Type: diskpart
6. Press Enter
7. Type: list disk
8. Press Enter
9. Remember the number of the disk  you want to convert.
10. Type: select disk “x”
11. Press Enter
12. Type: clean
13. Press Enter and Type: convert mbr
14. Press Enter
15. Disk #”x” is now being converted
16. You can type exit and hit Enter in Command Prompt to exit or continue setting up partitions on the new MBR disk.