Zip function problem

[psycoprogrammer]

I'm working with php5 on a windows box and I'm trying to read a file from a zip using zip_open. However, when i run the script, I a "call to undefinied function zip_open" error. I've enabled the extension=php_zip.dll line in my php.ini file and the only thing i can think of is that i need zziplib to be installed. I've googled how to do that on a windows machine for many fruitless hours. Also, here's what my code looks like:

$file = "output.txt";
$tax_file = "RMKR602A.ZIP";

$fh = fopen($file, 'a');
$unzip = zip_open($tax_file);
$zip_entry = zip_read($unzip);

if (zip_entry_open($unzip, $zip_entry, "r")){
$buf = zip_entry_read($zip_entry, zip_entry_filesize($zip_entry));
fwrite($fh, $buf);
} else {
echo "file not opened or read";
}

fclose($fh);
zip_entry_close($zip_entry);

And like i said, the error is when i try to do $unzip = zip_open($tax_file);

Any help on how to get this working by either installing zziplib on windows or changing some of the configuration would be greatly appreciated.