When ruuning an update query how do i get it to update the fields im updating to become blank. NOTE. the fields being update are linked to other tables so they are in the form of a combo box.

Just place " " in the Update To: row of the field or fields. Be very careful though, this will not only update the underlying tables but the linked tables as well. Also, this will not work if the fields you are updating are primary key fields or you have set the Required property to yes. Just curious as to why you would want to do this anyway?