i'm having some problems with my website. when i try to access a different page like a product page, i get a 404 error, but when i add index.php in the link it works. i've tried to update the database table core_config_data for the web/unsecure/base_url and web/secure/base_url so that they include the index.php but then for some reason my theme isn't applied and the whole layout of the website is messed up as no styling is applied. Is there anyway i could include the index.php so that it is included in all url links as without it my pages show 404 errors.
Any help is much appreciated