my $string = 'c:\\Windows';
my $search = '\\W';
my $qm = quotemeta($search);
my $raw = $string; $raw=~ s/$search/#/;
my $cooked = $string; $cooked =~ s/\Q$search/#/;
print <<"TEST"
original string: '$string'
search string: '$search'
search string after quotemeta: '$qm'
substitution without \\Q: '$raw'
substitution with \\Q: '$cooked'
TEST