Remove EFI System Partition or GPT Protective Partition in Windows
Dealing with Undeletable Partitions on Your Drive
It's not uncommon to encounter a situation where a partition on your storage drive appears undeletable. Several factors can contribute to this issue, preventing standard deletion methods from functioning.
One common example involves macOS systems. When Time Machine is configured on an external drive, the operating system automatically generates a 200 MB partition at the drive's beginning.
Why Standard Tools Fail
Typically, the built-in Windows Disk Management utility is unable to remove these types of partitions. Users will often find the "Delete Volume" function is disabled, indicated by a grayed-out state.
Despite this limitation, a method for partition removal does exist, although it isn't immediately obvious within the standard interface.
How to Remove Hidden Partitions
While the standard deletion option may be unavailable, the partition can still be removed. The process involves utilizing alternative methods within Disk Management to bypass the usual restrictions.
This allows for the complete reclaiming of the disk space occupied by the protected partition, restoring full control over the drive's storage capacity.
Important Precautions
To begin, it is crucial to avoid attempting this procedure on your Mac’s primary system drive. When utilizing Boot Camp and booting into Windows, an "EFI System Partition" will be visible at the outset of your Mac's internal drive. This partition should not be altered, as it is essential and intentionally protected.
Mac OS X also generates an EFI System Partition, or a GPT Protective Partition, at the start of an external drive during Time Machine setup. Should you continue to utilize the drive for Time Machine backups, this 200 MB partition must remain untouched.
The need to perform this action arises when a drive was formerly used for Time Machine backups but is no longer required for that purpose, and you intend to repurpose it. The initial 200 MB partition will resist deletion through standard methods, necessitating more advanced tools.
Be aware that this process will completely erase the entire external drive. It is not possible to remove only the 200 MB partition while preserving other existing partitions; the drive’s contents will be wiped, and a new partition table will be created. Ensure you have backups of any important files before proceeding.
If your files are stored in the Time Machine backup format and you lack access to a Mac, restoring those backups on a Windows system is possible.
Understanding the EFI Partition
The EFI System Partition is a small partition that contains the boot loader and other files necessary to start your Mac. It’s vital for the operating system to function correctly.
When to Remove the Partition
Removing the partition is only recommended when the drive is no longer used for Time Machine and you want to maximize its storage capacity. It allows for a clean slate when reformatting the drive.
Data Loss Warning
This process results in complete data loss. Therefore, backing up all important data from the external drive is absolutely essential before proceeding. Consider alternative backup solutions if you don't have a Mac available to restore Time Machine backups.
Steps to Consider
- Ensure the drive is not currently in use for Time Machine.
- Back up all important data.
- Understand that the entire drive will be erased.
Identifying the Target Disk
While the Disk Management utility won't be extensively utilized throughout this process, it serves a crucial initial purpose. Specifically, it allows you to identify and record the disk number associated with the partition you intend to remove. For instance, as illustrated in the accompanying screenshot, the external drive designated for partition removal is labeled "Disk 2."
It’s important to note that the numbering sequence begins at 0, meaning the third disk listed will be identified as "Disk 2." Retain this disk number, as it will be required in subsequent steps.
Should you not have already launched the Disk Management tool, access it by right-clicking the bottom-right corner of your screen in Windows 8 or 8.1 and selecting "Disk Management." Alternatively, across all Windows versions, press the Windows Key + R combination.
Then, type diskmgmt.msc into the Run dialog box and press Enter to initiate the tool.
Eliminating the Drive's Partition Structure
The next step involves completely erasing the drive’s partition table. This process will eliminate the 200 MB partition, alongside any other existing partitions on the disk, effectively resetting the drive. All data will be lost, necessitating a subsequent re-partitioning of the drive.
To initiate this, launch a Command Prompt window with Administrator privileges. In Windows 8 or 8.1, locate the bottom-left corner of the screen and right-click, then select "Command Prompt (Admin)." For Windows 7 users, search for "Command Prompt" in the Start menu, right-click the result, and choose "Run as Administrator."
Enter the following command and press Enter to execute it:
diskpart
This action initiates the diskpart utility, a command-line tool designed for advanced disk partitioning operations. Upon execution, the prompt will change to "DISKPART."
To display a list of all disks connected to your computer, type the following command:
list disk
Carefully note the disk number associated with the 200 MB partition. If you previously identified this number using Disk Management, it should remain consistent.
Now, input the following command, substituting '#' with the appropriate disk number:
select disk #
For instance, if the target disk is Disk 2, the command would be "select disk 2."
Exercise extreme caution when selecting the disk number to avoid unintended data loss.
Warning: The subsequent command will irrevocably wipe the drive. All data residing on any partition of the selected drive will be permanently lost. Double-check the disk number before proceeding!
Finally, execute the following command to remove all partition information from the drive. This action effectively clears the drive of all partitioning data, transforming it into a single, unallocated space:
clean
Once the 'clean' command completes, the process is finished. All partitions – including the 200 MB protected partition – will have been removed from the drive. You can exit the diskpart prompt using the following command, and then close the Command Prompt window:
exit
Establishing New Partitions
Related: Distinguishing GPT and MBR Partitioning Schemes
Return to the Disk Management tool; the drive will now be displayed as a single, undivided area labeled "Unallocated." Right-click on the drive identifier and choose the "Initialize Disk" option.
Selecting either the GPT or MBR partition style will enable the disk to operate normally. Subsequently, you can define and create the desired partitions on the disk, eliminating the previously persistent 200 MB partition.
Should you encounter a drive with undeletable partitions, or simply wish to restart the partitioning process entirely, the diskpart command offers a "clean" function. This will erase the partition table.