That’s a really inefficient way to do it.
Just use the $count variable you declared at the top, without any query_posts():
$count = 0;
while ( have_posts() ) : the_post();
if ( $count < 1 ) {
// first post
} elseif ( $count <= 4 ) {
// next 4 posts
} else {
// rest of the posts
}
$count++;
endwhile;
Also, it’s ‘showposts’ not ‘showpost’. Or use the newer ‘posts_per_page’.