See here: http://support.microsoft.com/kb/297800. Be careful.

Hi, Disk Management snap-in lets you convert empty MBR disk to GPT. Under GPT disk partition sytle, you can create more than 4 primary partitions and use disk space larger than 2TB. However, booting is only supported for 64-bit editions on UEFI-based systems.

I would strongly recommend to go through the document below - its great resource http://msdn.microsoft.com/en-us/windows/hardware/gg463525

hi how can i change current style to GPT? How can i find my current style? I can not format my hard.

See here: http://support.microsoft.com/kb/297800. Be careful.

Hi, Disk Management snap-in lets you convert empty MBR disk to GPT. Under GPT disk partition sytle, you can create more than 4 primary partitions and use disk space larger than 2TB. However, booting is only supported for 64-bit editions on UEFI-based systems.

I would strongly recommend to go through the document below - its great resource http://msdn.microsoft.com/en-us/windows/hardware/gg463525

Hi, Thank you for your post. You can change a disk from MBR to GPT partition style as long as the disk does not contain any partitions or volumes. Using the disk management UI or DISKPART convert gpt command. Please read Change a Master Boot Record Disk into a GUID Partition Table Disk article. If there are more inquiries on this issue, please feel free to let us know. Regards Rick Tan TechNet Community Support