How to delete a protected EFI disk partition
Partition problem? Here’s a short video on how to delete a protected EFI disk partition. When you use previously partitioned drives, sometimes when you go to disk manager, ( Control Panel > Admin. Tools > Computer Management > Disk Manager ), you will find that a disk you are trying to format has an EFI partition on ot that are protected and will not let you delete or format them when you right click. The way to get around this partition issue is to make a note of the disk number that has the protected partition (0, 1, 2, etc..). Exit disk manager and open your command prompt, (hit the windows key and type cmd into the search box ), when the cmd prompt box pops up in the menu, right click on it and run as administrator ( important ).
Once you are in the command prompt box, type the following command: diskpart and hit enter. Next type: list disk and hit enter. This should bring up a list of the current disks connected to your computer. The next step is to select the disk with the protected partition that you made a note of in disk manager. To do this type select disk 2 ( or whatever number your disk may be ), and hit enter. This should select the disk that you want, to check this type list disk and hit enter. This will bring up a list of disks again, this time you should see an asterisk beside you selected disk.
DO NOT GO ANY FURTHER UNLESS YOU ARE 100% ABSOLUTELY SURE YOU HAVE SELECTED THE CORRECT DISK – THE NEXT STEP WILL COMPLETELY WIPE OUT ANY DATA ON THE SELECTED DISK!!!
So here it is, if you are certain you have the correct drive type clean and hit enter. This will now erase all partitions and data from the drive with the protected partition. After it has completed your will be presented with a message that Diskpart has succeeded in cleaning the disk. Once completed you can exit the command prompt, go back into your disk manager, you should by now be notified that a new disk has been found and you need to initialize it. Once back in dis manager you can go ahead and reformat and use your newly cleaned drive.