not equal operator

<?php query_posts('category_name=-slider'); ?>

Now, the minus sign works in front of cat ID, not sure about name?
https://codex.www.ads-software.com/Function_Reference/query_posts#Category_Parameters

its didn’t work with category name

well, if you find out the category ID, I know this works

query_posts('cat=-3');

its work, but i need it by category name, any solution?

<?php $id = get_cat_id('design');
 query_posts("cat=-" . $id, '&paged=' . get_query_var('paged')); ?>

not sure if I have this exactly right, but get the ID for the cat, then exclude it

thanks dud! its work fine!
Thanks

Sure thing, glad it worked for you! Mark the thread as resolved using the dropdown on the right if you are happy with the help please