• You discard the results of readdir, the very file names you want.
• readdir returns file names without the path attached, so you need to do that yourself. Otherwise, -d and -M will look in the current directory instead of F:\test.
• You use $_, but never put a value in it.
• You use $File::Find::name, but you're not using File::Find.

use strict;
use warnings;

use File::Spec::Functions qw( catfile );

my $dir = 'F:\\test';
opendir(my $dh, $dir)
   or die("Can't open directory \"$dir\": $!\n");

my @dirs;
while (defined(my $fn = readdir($dh))) {
   next if $fn eq '.' || $fn eq '..';
   my $qfn = catfile($dir, $fn);
   if (-d $qfn && -M $qfn > 10) {
      push @dirs, $qfn;
   }
}

foreach (@dirs) {
   print("$_\n");
}
[download]

For future reference, wrap your code in <c>...</c> when posting on Perl Monks. That'll handle line breaks and encoding characters that need encoding (like <, [ and &).