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Access Disk Partitions

Be very careful. Always double-check the disk/partition. A wrong choice can wipe your OS.

Windows​

Example - Access EFI Partition & Delete Boot Loader Entry​

Goal: Temporarily mount the EFI/system partition, delete a boot folder, then restore things.

1. Open disk tool​

  1. Open Command Prompt as Administrator.
  2. Start disk tool:
diskpart

2. Select the correct disk and volume​

  1. List all disks:
list disk
  1. Select the disk (example: disk 0):
sel disk 0
  1. List volumes on that disk:
list vol
  1. Select the system/EFI volume (example: volume 1):
sel vol 1

3. Assign a drive letter to EFI partition​

  1. Assign a temporary letter (example: N):
assign letter=N

Now the EFI partition is accessible as N: in Explorer / terminal.

4. Delete unwanted boot loader folder​

  1. Exit disk tool (stay in admin terminal):
exit
  1. Go to the EFI partition:
N:
dir        # or: ls
  1. Enter EFI directory:
cd EFI
dir
  1. Delete the folder you don’t want in the boot menu:
rmdir Folder_Name

5. Cleanup: remove letter (and optional destructive actions)​

  1. Reopen diskpart and select the same disk & volume again:
diskpart
sel disk 0
sel vol 1
  1. Remove the drive letter so it goes back to hidden system state:
remove letter=N

Optional (destructive) operations on the selected volume​

  • Delete the whole volume (even if protected):
delete volume override
  • Format the volume (choose one filesystem):
format fs=NTFS

or

format fs=FAT32

Linux​

Format a Disk & Merge/Delete All Partitions​

Goal: Wipe a disk, create one new partition, format it, and mount it.

Only do this on a data disk, never on your OS disk. Double-check device names.

1. Identify the target disk​

  1. List disks and partitions:
lsblk
# or
sudo fdisk -l
  1. Choose your target disk, e.g. /dev/sdb.
  • Do not touch /dev/sda if that’s your OS drive.

2. Unmount all partitions on that disk​

  1. For each mounted partition (examples):
sudo umount /dev/sdX1
sudo umount /dev/sdX2
sudo umount /dev/sdX3

Replace sdX1, sdX2, … with real names like sdb1, sdb2.

3. Delete all partitions and create a new one (fdisk)​

  1. Open fdisk on the disk:
sudo fdisk /dev/sdX
# example: sudo fdisk /dev/sdb
  1. Inside fdisk (interactive):
  • d → delete a partition (repeat until no partitions left)
  • g → create new GPT partition table
  • n → create new partition
    • Press Enter for default partition number
    • Press Enter for default first sector
    • Press Enter for default last sector (use full disk)
  • w → write changes and exit

Now you have one new partition, e.g. /dev/sdX1 (/dev/sdb1).

4. Format the new partition​

  1. Create an ext4 filesystem and label it (optional label mydisk):
sudo mkfs.ext4 /dev/sdX1 -L mydisk
# example: sudo mkfs.ext4 /dev/sdb1 -L mydisk

5. Mount the partition​

  1. Create a mount point and mount it:
sudo mkdir -p /mnt/mydisk
sudo mount /dev/sdX1 /mnt/mydisk
# example: sudo mount /dev/sdb1 /mnt/mydisk

Now the new disk is available at /mnt/mydisk.