How can i access gdbm in win2k?

[luojie]

I had uncommented the line 'extension=php_dba.dll' in php.ini .
this is my example program.
<?php
$id = dba_open("d:\temp\test.db", "c", "db2");

if(!$id) {
echo "dba_open failed\n";
exit;
}

dba_replace("key", "This is an example!", $id);

if(dba_exists("key", $id)) {
echo dba_fetch("key", $id);
dba_delete("key", $id);
}

dba_close($id);
?>

Error:
Warning: dba_open(d:\temp\test.db,c): No such handler: db2 in D:\temp \test.php on line 2
dba_open failed

I change db2 by gdbm, ndbm, db3......still error.
Can you help me.