close $infh;
close $outfh;
my $mode = (stat('Tcl.dll'))[2];
my $newmode = $mode | 0220;
chmod($newmode, 'Tcl.dll');
unlink 'Tcl.dll';
File::Copy::copy( 'Tcl.dll_new', 'Tcl.dll') or die $!;
chmod($mode, 'Tcl.dll');
unlink('Tcl.dll_new');