use Win32::OLE qw( in );

my $wmi_service = Win32::OLE->GetObject("winmgmts:{impersonationLevel=impersonate}!\\\\.\\root\\cimv2")
   or die("Unable to connect to WMI: $!\n");

# DriveType 3 = local hard disk
my $disk_col = $wmi_service->ExecQuery("
   SELECT DeviceID
     FROM Win32_LogicalDisk
    WHERE DriveType = 3
");

my @drives = map { $_->DeviceID } in $disk_col;

local $, = ", ";
local $\ = "\n";
print @drives;