Step1: Hit “Windows Key” + “R” to open the run dialogue box and type “diskpart” and hit “OK” to open a black command prompt window.
Step2: Type “list disk” to display all the disks of your computer.
Step3: Type “select disk n”. Here n stands for the disk you want to work well.
Step4: Type “list partition” to display all the volumes on the hard drive.
Step5: Type “select partition n”. Here n stands for the volume you want to delete.
Step6: Type “delete partition override” to get rid of the volume.
Step7: Type “exit” to close the window.
Once you do that you have removed the OEM partition on the drive.