How about FileSystemObject:

code:
$objFSO = CreateObject("Scripting.FileSystemObject")
$Drives = $objFSO.Drives
For each $Drive in $Drives
	If $Drive.Drivetype=2
		? "Drive: " $Drive.Driveletter
		? "	Total Space: " $Drive.TotalSize
		? "	 Free Space: " $Drive.FreeSpace
		?
	Endif
Next