Bah humbug! I should really read the posts I reply to. Substituting 'winspool.drv' (as you mentioned) into my code in the other post, and using EnumPortsA gives:

Updated: Simplified last line of code. With thanks to util.

#! perl -slw
use strict;
use Win32::API::Prototype;
ApiLink(
    'Winspool.drv', q[
        BOOL EnumPortsA( 
           LPTSTR pName, DWORD Level, LPBYTE pPorts, DWORD cbBuf, 
           LPDWORD pcbNeeded, LPDWORD pcReturned 
        )
    ],
) or die $^E;

my $bytesNeeded = pack 'V', 0;
my $portsRecvd  = pack 'V', 0;
my $buf = chr(0) x 2000;

EnumPortsA( 0, 1, $buf, 2000, $bytesNeeded, $portsRecvd ) or die $^E;

$bytesNeeded = unpack 'V', $bytesNeeded;
$portsRecvd  = unpack 'V', $portsRecvd;

#print "b:$bytesNeeded p:$portsRecvd";

my @pointers = unpack "V$portsRecvd", $buf;
#printf "%08x\n", $_ for @pointers;

#print unpack 'p', $_ for unpack "(a4)$portsRecvd", $buf;
## The above simplifies to (thanks [util])
print for unpack "(p)$portsRecvd", $buf;

__END__
C:\test>junk9
USB001
COM1:
COM2:
COM3:
COM4:
FILE:
LPT1:
LPT2:
LPT3:
NUL:
[download]

Which I think is all that's required. If you need the extended information, then you'll need to work a bit harder.

I'll have to add the export lists of *.DRV (and probably some other extensions) to my big list!