Can't find OXReserved on Disk Utiity
You no long have a OXReserved partition. The partition shown in you question is the Windows Recovery partition. This partition is created when Windows is installed using the Boot Camp Assistant. (Although, the partition can also be created when someone installs Windows without using the Boot Camp Assistant.) A correct installation of Windows should include a BOOTCAMP partition and a Windows Recovery partition. 

To remove the Windows Recovery partition using the Disk Utility, you would first have to remove the BOOTCAMP partition.


  Note: Normally, the Boot Camp Assistant is used to remove Windows.