Get disk & partition index number from driver letter

[doestergaard]

This is a tough one and I hope some of you guys can help me out.

I need to know the disk & partition index numbers from a partition which has Windows installed.

The script will search for the Windows folder and retrieve its drive letter.

I just don't how to manage this. I have tried WMI, but seems tricky and not what im after.

 

Any help is appreciated!

Thanks in advance

[water]

Did you search the forum? I know this has already been discussed.

[water]

How about >this thread?

[doestergaard]

Yes i did, but as far as I can tell it only shows how to get the drive letter only, i need the disk number and partition number FROM a driver letter, for instance:

Drive C: is on disk 0 partition 2

[water]

When running this script (generated by the AutoIt tool ScriptoMatic) do you get the correct result?

; Generated by AutoIt Scriptomatic

$wbemFlagReturnImmediately = 0x10
$wbemFlagForwardOnly = 0x20
$colItems = ""
$strComputer = "localhost"

$Output=""
$Output = $Output & "Computer: " & $strComputer  & @CRLF
$Output = $Output & "==========================================" & @CRLF
$objWMIService = ObjGet("winmgmts:\\" & $strComputer & "\")
$colItems = $objWMIService.ExecQuery("SELECT * FROM Win32_LogicalDiskToPartition", "WQL", _
                                          $wbemFlagReturnImmediately + $wbemFlagForwardOnly)

If IsObj($colItems) then
   For $objItem In $colItems
      $Output = $Output & "Antecedent: " & $objItem.Antecedent & @CRLF
      $Output = $Output & "Dependent: " & $objItem.Dependent & @CRLF
      $Output = $Output & "EndingAddress: " & $objItem.EndingAddress & @CRLF
      $Output = $Output & "StartingAddress: " & $objItem.StartingAddress & @CRLF
      if Msgbox(1,"WMI Output",$Output) = 2 then ExitLoop
      $Output=""
   Next
Else
   Msgbox(0,"WMI Output","No WMI Objects Found for class: " & "Win32_LogicalDiskToPartition" )
Endif

[doestergaard]

Yes

But how does it know its drive C?

Thank you very much for your help! Really appreciate it

[water]

Because the driver letter is part of $obj.Dependent

[water]

This should display a MsgBox for all drives displaying disk # and partition #.

$objWMIService = ObjGet("winmgmts:\\.\root\CIMV2")
$WMIQuery = $objWMIService.ExecQuery("SELECT * FROM Win32_LogicalDiskToPartition")
For $obj In $WMIQuery
    $sAntecedent = $obj.Antecedent
    $sDependent = $obj.Dependent
    $iDisk = StringMid($sAntecedent, StringInStr($sAntecedent, "Disk #") + 6, 1)
    $iPartitiion = StringMid($sAntecedent, StringInStr($sAntecedent, "Partition #") + 11, 1)
    $sDrive = StringMid($sDependent, StringInStr($sDependent, 'DeviceID="') + 10, 1)
    MsgBox(0, $sDrive & " Drive", $sDrive & " Drive is on Disk #" & $iDisk  & ", partition #" & $iPartitiion)
Next

Works for one digit disk # and partition #.

[doestergaard]

Holy, sh*t! Thanks!

You are mig hero

Just a final question. I will only need the integer for Building a diskpart script for Windows PE. The above code will detect the Windows partition yes?

Once Again, thank you very much!!

[water]

Full description of the Win32_LogicalDiskToPartition class can be found here.

[doestergaard]

Whoops, sry, it only gives back the int, thanks!

[doestergaard]

One more thing. Diskpart says that drive C has partition number 2 The result i get from your code is 1

Edited January 13, 2015 by doestergaard

[water]

What does the Windows Device Manager display?

I'm running Windows in a VM and get partition number 1 because partition 0 is used by Windows itself.