There are a number of churches in Harlow but I think the only one relevant to your time scale is St. Mary and St. Hugh, Harlow. At Essex RO I searched the fiche for that parish fice 1 of 2. It is a mixture of marriages, baptisms and burials all jumbled together and entered in ABC order rather than date. I got cheesed off with that and decided to see what transcripts were available. The only transcript is in the Essex Marriage Registers T/R 203 Vol 61 and the situation is made clear by the opening sentence: "In 1814 the chest containing the registers for this parish was stolen and the registers have never been recovered....." It goes on to describe how the marriage transcript was prepared from various sources and it includes on page 3801 Apr 23 1805 William WHITAKER of Latton married Mary BRADLEY. I went back to the microfiche to look for any WHITAKER baptisms but there were none. It may be worthwhile posting a new request for Latton.