Learn how to format your operating systems drive in Windows PC (format a locked system drive on boot with command prompt ) and how to format a BitLocker encrypted external hard drive in Windows and OS X.

1. How to Open and Use a BitLocker Locked System or
External Hard Drive without Password/Recovery Key
How to format BitLocker encrypted system disk and USB drive on Mac and PC
If you encounter a prompt to use a BitLocker PIN or password to unlock the system
drive or USB drive, but you do not know the password and have a valid Recovery key
in your related Microsoft account, you will not be able to access system (Your PC) or
that locked removable drive or external hard drive.
However, formatting a hard drive allows you to use it on your computer to store files
and install programs on. Two of the most popular operating systems, Windows and
Mac OS, have built-in formatting utilities that make formatting external drives more
convenient.
Learn how to format your operating systems drive in Windows PC and how to format
a BitLocker encrypted external hard drive in Windows and OS X.
• Format your boot drive (Windows)
• Format an encrypted removable drive(Windows)
• Format an encrypted external hard drive(Mac)
Formatting a hard drive and an external hard drive is usually a fairly straightforward
process. There are still many situations where you need to format your hard drive.
1. Incompatible file system errors
In most cases, you must convert FAT32 to NTFS or NTFS to FAT32 by formatting so
that you can use a specific drive on Windows, Mac or other platforms.
2. To clear the Windows operating system installed on the hard drive, formatting is
the main job.
3. The hard drive is broken or the bad track is broken. Or, if access is denied due to
the RAW file system, Windows will ask you to format it before using it.

2. Format the boot drive (Windows)
To format a system drive, you need to boot the device from the Windows 10 USB
installation media. If you don't have Windows installation media, you can create one
using Microsoft's media creation tools.
To do this, follow these steps:
• On a working PC, go to the Microsoft software download website.
• Download the Windows 10 media creation tool and then run it.
• Select Create installation media for another PC.
• Choose a language, edition, and architecture (64-bit or 32-bit).
• Follow the steps to create installation media, and then select Finish.
Step 1: Connect the installation media you created to your nonfunctional PC, and
then turn it on. Boot Windows from the installation media. Check your PC
manufacturer's website for info on how to change your PC's boot order.
Step 2: On the initial setup screen, press Shift + F10. This will bring up a command
prompt window.

3. Step 3: Run the following command, and then press Enter.
Type diskpart
Type list disk
Type Select disk #. # is the drive number they want to install to.
Type Clean
Type Convert GPT
Type Exit
Boot to the Windows 10 installation media and start system recovery or the Windows
installation process.
2 Ways to Format a Removable drive in Windows Operating
System
Format a removable drive with command prompt

4. Step 1: Open an elevate command prompt.
Press Win + X and hit A on the keyboard, this will open Command Prompt (Admin).
Step 2: Run the following command and press Enter.
Type diskpart
Type list disk
Type Select disk #. # is the drive number of removable disk.
Type Clean
After formatting the removable driver, it is an unallocated disk, we need to create a
simple new volume for it. To do this, press Win+X and hit K on the keyboard to open
the Disk Management.
Right-click an unallocated region on your hard disk, and then select New Simple
Volume. In the New Simple Volume Wizard, select Next.

5. Enter the size of the volume you want to create in megabytes (MB) or accept the
maximum default size, and then select Next. Accept the default drive letter or choose
a different drive letter to identify the partition, and then select Next.
Format removable drive with Windows Quick format
If you want to format USB, Windows Quick Format is easy to use.
1. Press Win+X and hit K to open Disk Management.
2. Right-click the volume that you want to format, and then select Format.
3. To format the volume with the default settings, in the Format dialog box,
select OK, and then select OKagain.
Format USB or external hard drive with Disk Utility on Mac
1. Connect the USB or external hard drive to your Mac computer.
2. Launch the Disk Utility by clicking "Applications" > "Utilities".
3. Locate and click on your USB drive in Disk Utility then click on "Erase".

6. 4. Next to "Format", click the contextual menu and choose between several file systems:
OS X Extended (Case-sensitive, Journaled, Encrypted)
This is the same as the standard OS X Extended (Case-sensitiive) file systembut with encryption.
MS-DOS (FAT)
This is the most widely compatible file system, but it has some limitations that files can only be
4GB or less in size each. Avoid this file system unless you have a device that requires FAT32.
ExFAT
ExFAT is almost as widely compatible as older FAT file systems, but doesn’t have the limitations.
You should use this file system if you may share the drive with Windows PCs and other devices.
ExFAT is the ideal cross-platform file system.
5. Reset the drive name and click "Erase", confirm the operation on the next pop-up
window.