My version:

alias _hdd {
  var %e, %b = 1

  .comopen dv Scripting.FileSystemObject
  if ($comerr) {
    %e = Unable to create a FileSystemObject
  }
  elseif (!$com(dv,drives,3,dispatch * dv2)) {
    %e = Unable to get drives from FileSystemObject
  }
  elseif ($com(dv2)) {
    while ($comval(dv2,%b,path) $comval(dv2,%b,serialnumber) != $chr(32)) {
      !echo -: $v1
      inc %b
    }
  }
  else {
    %e = No drives found.
  }

  :error
  if ($com(dv)) .comclose $v1
  if ($com(dv2)) .comclose $v1
  if ($iif(%e,$v1,$error)) {
    !echo - Error: $v1
    reseterror
  }  
}