Source code for bootdriv.vbs

' Check command line parameters (none required)

```
If WScript.Arguments.Count > 0 Then
```
```
	strMsg = vbCrLf _
```

	       & "BootDriv.vbs,  Version 1.00" & vbCrLf _

	       & "Return drive letter from which computer was booted" _

```
	       & vbCrLf & vbCrLf _
```

	       & "Usage:  CSCRIPT  BOOTDRIV.VBS" _

```
	       & vbCrLf & vbCrLf _
```

	       & "Written by Rob van der Woude" & vbCrLf _

	       & "http://www.robvanderwoude.com" _

```
	       & vbCrLf & vbCrLf _
```

	       & "Code to associate partitions with drive letters found on" & vbCrLf _

	       & "TechNet Script Center, section Disks and File Systems:" & vbCrLf _

	       & "http://www.microsoft.com/technet/treeview/default.asp?url=/technet/scriptcenter/dfs/ScrDFS37.asp" & vbCrLf _

	       & "(C) 2003 Microsoft Corporation"

```
	WScript.Echo strMsg
```
```
	WScript.Quit(1)
```
```
End If
```
```
 
```
```
' Don't stop at errors
```
```
On Error Resume Next
```
```
 
```
```
' For the local computer only
```
```
strComputer = "."
```
```
 
```

' Use WMI to get boot drive as disk and partition numbers

Set objWMIService = GetObject( "winmgmts://" & strComputer & "/root/cimv2" )

Set colItems = objWMIService.ExecQuery( "Select * From Win32_DiskPartition Where BootPartition = true", , 48 )

```
For Each objItem in colItems
```

    strBootDiskIndex = objItem.DiskIndex

```
    strBootPartition = objItem.Index
```
```
Next
```

' Format the result to compare it with the result of next query

strBootDisk = "Disk #" & strBootDiskIndex & ", Partition #" & strBootPartition

```
 
```

' Associate partitions with drive letters.

' Script found on TechNet Script Center, section Disks and File Systems:

' http://www.microsoft.com/technet/treeview/default.asp?url=/technet/scriptcenter/dfs/ScrDFS37.asp

```
' (C) 2003 Microsoft Corporation
```

Set objWMIService = GetObject( "winmgmts:{ impersonationLevel=Impersonate }!//" & strComputer )

Set colDiskDrives = objWMIService.ExecQuery( "Select Caption, DeviceID FROM Win32_DiskDrive" )

```
For Each objDiskDrive In colDiskDrives
```

	strEscapedDeviceID = Replace( objDiskDrive.DeviceID, "\", "\\", 1, -1, vbTextCompare )

	Set colDiskPartitions = objWMIService.ExecQuery( "Associators Of {Win32_DiskDrive.DeviceID=""" & strEscapedDeviceID & """} Where AssocClass = Win32_DiskDriveToDiskPartition" )

	For Each objDiskPartition In colDiskPartitions

		Set colLogicalDisks = objWMIService.ExecQuery( "Associators Of {Win32_DiskPartition.DeviceID=""" & objDiskPartition.DeviceID & """} Where AssocClass = Win32_LogicalDiskToPartition" )

		For Each objLogicalDisk In colLogicalDisks

			If objDiskPartition.DeviceID = strBootDisk Then

				WScript.Echo vbCrLf & "Boot Drive = " & objLogicalDisk.DeviceID

```
			End If
```
```
		Next
```
```
	Next
```
```
Next
```
```
 
```