This VBS script will write all the Active Directory (AD) Domain Controllers local disk space information to excel for the local AD domain.

VBS Script:

Set objExcel = CreateObject("Excel.Application")
objExcel.Visible = True
objExcel.Workbooks.Add
intRow = 2

objExcel.Cells(1, 1).Value = "Server Name"
objExcel.Cells(1, 2).Value = "Drive Letter"
objExcel.Cells(1, 3).Value = "Total Space (GB)"
objExcel.Cells(1, 4).Value = "Free Space (GB)"

Set objDomain = GetObject("LDAP://RootDSE")
strDomain = objDomain.Get("DefaultNamingContext")
Set objOU = GetObject("LDAP://ou=Domain Controllers," & strDomain)
For Each strServer In objOU

Set objWMIService = GetObject("winmgmts:\\" & strServer.CN & "\root\CIMV2")
Set colItems = objWMIService.ExecQuery("Select * From Win32_LogicalDisk Where DriveType = 3")
For Each objItem in colItems

objExcel.Cells(intRow, 1).Value = strServer.Cn
objExcel.Cells(intRow, 2).Value = objItem.Name
objExcel.Cells(intRow, 3).Value = (FormatNumber(objItem.Size/ 1024^3, 1)) & " GB"
objExcel.Cells(intRow, 4).Value = (FormatNumber(objItem.Freespace/ 1024^3, 1)) & " GB"
intRow = intRow + 1
Next
Next

objExcel.Range("A1:D1").Select
objExcel.Selection.Font.ColorIndex = 11
objExcel.Selection.Font.Bold = True
objExcel.Range("A1:D1").Select
objExcel.Cells.EntireColumn.AutoFit

MsgBox "Done"