I have scripted FreeSpace.vbs to retrieve the freespace on each of my hard drives.

If you just want to display the information, open a CMD.EXE prompt and type:

cscript //nologo <FolderPath>\FreeSpace.vbs

You will receive a display like the following, where the free space is in megabytes.

C: 15345
D: 31329

If you wanted to process the results in a batch file:

for /f "Tokens=1*" %%a in ('<b>cscript //nologo <FolderPath>\FreeSpace.vbs</b>') do (
 set drive=%%a
 set /a freespace=%%b
 ...
 ...
)
FreeSpace.vbs contains:
strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
    & "\{impersonationLevel=impersonate\}!\\" & strComputer & "\root\cimv2")
Set colDisks = objWMIService.ExecQuery _
    ("Select * from Win32_LogicalDisk Where DriveType = 3")
For Each objDisk in colDisks
Wscript.Echo objDisk.DeviceID  & " " _
    & Int (objDisk.FreeSpace / 1024 / 1024)
Next