Adding a summary report and disk information to VB Script - windows

Question

I was hoping someone could help me with this code. I wanted to add two things to this script but can't seem to get it working at all.
The script works fine but what isn't working is trying to add the disk information and trying to create a summary report for total size of disk.
at the end of it I'm trying to make an output of what
wmic diskdrive list brief /format:list
would give you.
something like this:
Caption=WDC WD2500BEKT-75PVMT1
DeviceID=\\.\PHYSICALDRIVE0
Model=WDC WD2500BEKT-75PVMT1
Partitions=1
Size=250056737280
Here is the script so far
Option Explicit
const strComputer = "."
const strReport = "c:\path\to\file"
Dim objWMIService, objItem, colItems
Dim strDriveType, strDiskSize, txt
Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
Set colItems = objWMIService.ExecQuery("Select * from Win32_LogicalDisk WHERE DriveType=3")
txt = "Drive" & vbtab & "Size" & vbtab & "Used" & vbtab & "Free" & vbtab & "Free(%)" & vbcrlf
For Each objItem in colItems
DIM pctFreeSpace,strFreeSpace,strusedSpace
pctFreeSpace = INT((objItem.FreeSpace / objItem.Size) * 1000)/10
strDiskSize = Int(objItem.Size /1073741824) & "Gb"
strFreeSpace = Int(objItem.FreeSpace /1073741824) & "Gb"
strUsedSpace = Int((objItem.Size-objItem.FreeSpace)/1073741824) & "Gb"
txt = txt & objItem.Name & vbtab & strDiskSize & vbtab & strUsedSpace & vbTab & strFreeSpace & vbtab & pctFreeSpace & vbcrlf
Next
writeTextFile txt, strReport
wscript.echo "Report written to " & strReport & vbcrlf & vbcrlf & txt
' Procedure to write output to a text file
private sub writeTextFile(byval txt,byval strTextFilePath)
Dim objFSO,objTextFile
set objFSO = createobject("Scripting.FileSystemObject")
set objTextFile = objFSO.CreateTextFile(strTextFilePath)
objTextFile.Write(txt)
objTextFile.Close
SET objTextFile = nothing
end sub

Answer 1

The wmic call and your script do entirely different things. The former queries the Win32_DiskDrive class to gather information about the physical disks, whereas the latter queries the Win32_LogicalDisk class to gather information about the volumes.
You can reproduce the output of the wmic command with something like this:
Set wmi = GetObject("winmgmts://./root/cimv2")
For Each disk In wmi.ExecQuery("SELECT * FROM Win32_DiskDrive")
WScript.Echo "Caption=" & disk.Caption & vbNewLine _
& "DeviceID=" & disk.DeviceID & vbNewLine _
& "Model=" & disk.Model & vbNewLine _
& "Partitions=" & disk.Partitions & vbNewLine _
& "Size=" & disk.Size
Next
However, the size returned by this query is the raw capacity of the physical disk. At this level you can't distinguish if a block is "free" or "used". Those are concepts that apply to filesystems. On that level, a sector either does or doesn't contain one or more files or file fragments. It's "free" when it doesn't contain any file and "used" otherwise. On that level, you don't get any information about "partitions", though, because those exist on a lower level (partitions contain filesystems).
What you need to do is decide which information you actually want to report, and then choose the appropriate properties from the relevant WMI class(es).