I suspect that you aren't connecting to the dsn correctly from your XP box. Hence, after the first line, the object $db is undefined. Something like:
my $db = new Win32::ODBC("dsn=A3T;UID=shenriks;PWD=changeme0");
die "Cannot connect to dsn A3T" unless ( defined $db );
or something like that. From the Win32::ODBC doc
Next, create a data connection to your DSN:
NOTE: MyDSN can be either the DSN as defined in the ODBC Administrator, or it can be an honest-to-God DSN Connect String.
Example: "DSN=My Database;UID=Brown Cow;PWD=Moo;"
You should check to see if $Data is indeed defined, otherwise there has been an error.
$Data = new Win32::ODBC("MyDSN");
Also, look into code tags for your posts. See this node 17558
for more details.
Updated: added link to writeup formatting node