How to expand your Windows 10 Pro AWS Instance’s C drive

These instructions can be followed to grow your Windows 10 AMI C drive to 200GB. Our Windows 11 will auto-expand as the partitioning was improved. However, you may still find this useful for any Windows version instance, and even for actual physical PC/Server Windows installs.

You will have to delete the recovery partition, which can be recreated at another time (instructions not included)
  1. Using the Launch Wizard, configure storage to be 200Gb for the Root volume, be sure to complete all of the other required Launch information, then Launch the instance.
  2. Wait for instance to be ready – about 20 minutes for a t3.xlarge. Log in using Remote Desktop, enter Administrator for user name, and the Instance ID for password.
First, Delete the Rescue Partition
  1. Right-click the Start menu and select Windows PowerShell (Admin) or Command Prompt (Admin). Be sure to click ok in security warning to allow to run as Administrator
  2. Type diskpart and press Enter, then type list disk and press Enter.
  3. A list of disks displays. Type select disk # (where # is the number of the disk with the recovery partition) and press Enter.
  4. Type partition list and press Enter. Note the recovery partition number, usually 3 in this AMI
  5. Type select partition 3
  6. Type delete partition override and press Enter. You can always create a new one later.
  7. After you see a confirmation message, you can close the PowerShell/Command Prompt.

Next, Expand the C Partition to Use the Unallocated Space

If you want to expand another partition to use the extra space, then the unallocated space must appear to the immediate right of that partition in the Disk Management tool. This is why we had to delete the Rescue partition first.
To extend a partition:

  1. Right-click the Start menu and select Disk Management.
  2. Right-click the partition you want to expand, (C:), and select Extend Volume.
  3. Select Next to continue the wizard.
  4. Enter how much of the unallocated space you want to use, in most cases just take the defaults, then select Next.
  5. Select Finish to terminate the wizard. The Windows partition will be resized to include the extra space.