I have HP Core I5-3210M 2.50 GHZ with Windows 8 installed by default. I created another partition with EaseUs and then tried to install Windows 8.1 but it gives error some thing related to GPT disk. I search on net and found that I have to convert disk/partition to MBR.

How to convert single partition or disk to MBR format so I can install Win 8.1 on same laptop. Then I have both 8.0 and 8.1 on same laptop and I can switch between those.

There is no data on 8.1 partition so there is no harm in formatting it (even I deleted this partition and created new in the beginning of 8.1 setup but it failed) but there is data on this disk and I can't format whole disk.

So how to convert disk/partition to MBR safely without losing data??

Any help please.