EnableExplicit

#IOCTL_DISK_GET_DRIVE_LAYOUT = $7400c    ; HEX
#IOCTL_DISK_GET_DRIVE_LAYOUT_EX = $70050 ; HEX

Structure PARTITION_INFORMATION_MBR Align #PB_Structure_AlignC
  PartitionType.b
  BootIndicator.b
  RecognizedPartition.b
  HiddenSectors.i
EndStructure

Structure PARTITION_INFORMATION_GPT Align #PB_Structure_AlignC
  TypeGuid.b[16] ;GUID
  IDGuid.b[16]   ;GUID
  Attributes.q
  Name.c[36]
EndStructure

Structure PARTITION_INFORMATION_EX Align #PB_Structure_AlignC
  PartitionStyle.w
  StartingOffset.d
  PartitionLength.d
  PartitionNumber.i
  RewritePartition.b
  IsServicePartition.b
  StructureUnion
    piMBR.PARTITION_INFORMATION_MBR
    piGPT.PARTITION_INFORMATION_GPT
  EndStructureUnion
EndStructure

Structure DRIVE_LAYOUT_INFORMATION_MBR Align #PB_Structure_AlignC
  Signature.i
  CheckSum.i
EndStructure

Structure DRIVE_LAYOUT_INFORMATION_GPT Align #PB_Structure_AlignC
  DiskId.b[16]
  StartingUsableOffset.q
  UsableLength.q
  MaxPartitionCount.l
EndStructure

Structure DRIVE_LAYOUT_INFORMATION Align #PB_Structure_AlignC
  PartitionCount.w
  Signature.w
  PartitionEntry.PARTITION_INFORMATION_EX[8192]
EndStructure

Structure DRIVE_LAYOUT_INFORMATION_EX Align #PB_Structure_AlignC
  PartitionStyle.w
  PartitionCount.w
  StructureUnion
    dliMBR.DRIVE_LAYOUT_INFORMATION_MBR
    dliGPT.DRIVE_LAYOUT_INFORMATION_GPT
  EndStructureUnion
  PartitionEntry.PARTITION_INFORMATION_EX[8192]
EndStructure

Procedure _CreateFile_PHYSICALDRIVE_ONLY_READ(iDrive.i)
  Protected hDevice = CreateFile_("\\.\PHYSICALDRIVE" + iDrive, #GENERIC_READ, #FILE_SHARE_READ , 0, #OPEN_EXISTING, 0, 0)
  ProcedureReturn hDevice
EndProcedure

Procedure$ _WinAPI_count_Partitions(iDrive.i)
  Protected *struc.DRIVE_LAYOUT_INFORMATION_EX
  Protected Ret$ = "Unknown", iBytesRet
  Protected hDevice = _CreateFile_PHYSICALDRIVE_ONLY_READ(iDrive)
  If hDevice <> #INVALID_HANDLE_VALUE ; <> 0
    *struc = AllocateStructure(DRIVE_LAYOUT_INFORMATION_EX)
    If *struc
      If DeviceIoControl_(hDevice, #IOCTL_DISK_GET_DRIVE_LAYOUT_EX, 0, 0, *struc, SizeOf(DRIVE_LAYOUT_INFORMATION_EX), @iBytesRet, 0)
        Debug "Disk #" + iDrive
        Debug "PartitionStyle: " + *struc\PartitionStyle
        Select *struc\PartitionStyle
          Case 0 ; MBR
            Debug "Signature: " + *struc\dliMBR\Signature
            Debug "Partition Count on MBR Disks: " + *struc\PartitionCount
          Case 1 ; GPT
            Debug "Partition Count on GPT Disks: " + *struc\PartitionCount
        EndSelect
      Else
        Debug "DeviceIoControl Failed on Disk #" + iDrive
      EndIf
      
      FreeStructure(*struc)
    EndIf
  Else
    Debug "Have error when opening Disk #" + iDrive
  EndIf
  CloseHandle_(hDevice)
EndProcedure

Debug _WinAPI_count_Partitions(0); for my MBR Disk
Debug _WinAPI_count_Partitions(1); for my GPT Disk