ubuntu@ubuntu:~$ sudo parted /dev/sda
GNU Parted 3.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Model: ATA KINGSTON SNV425S (scsi)
Disk /dev/sda: 64.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start   End     Size    Type     File system  Flags
 1      1049kB  525MB   524MB   primary  ntfs         boot
 2      525MB   64.0GB  63.5GB  primary  ntfs

(parted) rm 1
(parted) rm 2
(parted) print
Model: ATA KINGSTON SNV425S (scsi)
Disk /dev/sda: 64.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start  End  Size  Type  File system  Flags

(parted) mktable msdos
Warning: The existing disk label on /dev/sda will be destroyed and all data on
this disk will be lost. Do you want to continue?
Yes/No? y
(parted) quit
Information: You may need to update /etc/fstab.

ubuntu@ubuntu:~$ sudo cat /proc/partitions
major minor  #blocks  name

   1        0      65536 ram0
   1        1      65536 ram1
   1        2      65536 ram2
   1        3      65536 ram3
   1        4      65536 ram4
   1        5      65536 ram5
   1        6      65536 ram6
   1        7      65536 ram7
   1        8      65536 ram8
   1        9      65536 ram9
   1       10      65536 ram10
   1       11      65536 ram11
   1       12      65536 ram12
   1       13      65536 ram13
   1       14      65536 ram14
   1       15      65536 ram15
   7        0    1399872 loop0
   8        0   62522712 sda
   8        1     512000 sda1
   8        2   62008320 sda2
   8       16    1956864 sdb
   8       17    1955840 sdb1
ubuntu@ubuntu:~$ sudo parted /dev/sda
GNU Parted 3.2
Using /dev/sda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Model: ATA KINGSTON SNV425S (scsi)
Disk /dev/sda: 64.0GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:

Number  Start   End     Size    Type     File system  Flags
 1      1049kB  525MB   524MB   primary  ntfs         boot
 2      525MB   64.0GB  63.5GB  primary  ntfs

(parted) quit
ubuntu@ubuntu:~$ sudo gdisk /dev/sda
GPT fdisk (gdisk) version 1.0.1

Partition table scan:
  MBR: MBR only
  BSD: not present
  APM: not present
  GPT: not present


***************************************************************
Found invalid GPT and valid MBR; converting MBR to GPT format
in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by
typing 'q' if you don't want to convert your MBR partitions
to GPT format!
***************************************************************


Command (? for help): o
This option deletes all partitions and creates a new protective MBR.
Proceed? (Y/N): y

Command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!

Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sda.
The operation has completed successfully.
ubuntu@ubuntu:~$ sudo sfdisk -d /dev/sda
label: dos
label-id: 0x56ed0d2d
device: /dev/sda
unit: sectors

/dev/sda1 : start=        2048, size=     1024000, type=7, bootable
/dev/sda2 : start=     1026048, size=   124016640, type=7
ubuntu@ubuntu:~$ sudo fdisk -l /dev/sda
Disk /dev/sda: 59.6 GiB, 64023257088 bytes, 125045424 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x56ed0d2d

Device     Boot   Start       End   Sectors  Size Id Type
/dev/sda1  *       2048   1026047   1024000  500M  7 HPFS/NTFS/exFAT
/dev/sda2       1026048 125042687 124016640 59.1G  7 HPFS/NTFS/exFAT
ubuntu@ubuntu:~$