1. Edit your wp-config.php file and enter something like:
WordPress memory can be different to the server – you need to set this regardless of server memory settings
2. If you have access to your PHP.ini file, change the line in PHP.ini
If your line shows 32M try 64M:
memory_limit = 64M ; Maximum amount of memory a script may consume (64MB)
3. If you don’t have access to PHP.ini try adding this to an .htaccess file:
php_value memory_limit 64M
4. If none of the above works then talk to your host.