1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'touch screen monitor" and pt.tags_status=1 and pd.language_id=1 group by pt.prod' at line 1
in:
[select p.products_id,p.products_image,p.products_tax_class_id,pd.products_name from popular_tags as pt,products as p,products_description as pd WHERE pt.products_id=p.products_id and p.products_id=pd.products_id and pt.tags_name="7" touch screen monitor" and pt.tags_status=1 and pd.language_id=1 group by pt.products_id order by p.best_selling_sort desc]