1. Edit your wp-config.php file and enter something like:
define('WP_MEMORY_LIMIT', '256M');
2. If you have access to your PHP.ini file, change the line in PHP.ini
If your line shows 32M try 256M:
memory_limit = 256M ; Maximum amount of memory a script may consume (256MB)
3. If you don’t have access to PHP.ini try adding this to the .htaccess file:
php_value memory_limit 256M
4. If none of the above works then talk to your host.