Any candidate can request a manual recount in a county under 102.166 (4) provided that such a request is made prior to vote certification by the canvassing board (presumably the infamous 7 day deadline under 102.112).  If a canvassing board agrees to conduct the manual recount, it must first do a manual recount of a sample of its ballots pursuant to 102.166 (4)(d).   According to 102.166(5), if that sample manual recount "indicates an error in the vote tabulation which could affect the outcome of the election, the county canvassing board shall" do one of three things, one of which is conduct a full manual recount of all ballots .  Katherine Harris issued a legally advisory opinion in which she added the word system onto the phrase error in vote tabulation in an attempt to convince counties they had to have an error with their machines to conduct a manual recount.  However, the State Supreme Court ruled that the plain language of the statute does not limit the error in the vote count to only
machine error.

102.166(7) then lays out guidelines for manual recounts in which bipartisan counting teams are "to determine a voter's intent in casting a ballot".

Gore filed the necessary requests in these four counties on November 9.  They all conducted their sample recounts and eventually ruled that the number of new votes found (i.e., the vote tabulation error) suggested that a full manual recount might turn up enough new votes for either candidate to change the outcome of the election.  Once such a conclusion is reached, they were all required to do something about it.  They all chose a full manual recount.  However, thanks to a variety of delays (most of which were caused by the Bush campaign, Bush's lawyers, and Secretary of State Harris), only Volusia County finished its count by November 14.  Since the provisions of the manual recount provision require counting past the deadline if they are to have any statutory significance, these counties requested additional time to fulfill their obligations under Section 102.166.  However, Harris ruled that she would not accept any late returns, even those that were the result of procedural compliance with another statutory provision, because 102.112 essentially prevented her from doing so.  The Florida Supreme Court ruled against Harris in this regard partially because she was essentially using her discretionary power under 102.112 to avoid her statutory obligation to enforce 102.166.   

The primary role of the executive branch is the enforcement of all the legislative branch's statutes.  As an executive officer, the
Secretary of State has a legal obligation to enforce every aspect of Florida's election code, not just the ones that improve her
candidate's chances for victory.  In the course of exercising the discretionary authority granted her by one section of a statute
(in this case 102.112), she can not forego her obligation to enforce other sections of that same statute such as 102.166 (or any
other statute for that matter).  In other words, the executive branch's ability to interpret law and exercise discretion can not
render obsolete or ignore other legislative provisions -- executives do not have that power because their foremost duty is to
enforce all the laws; any interpretive and discretionary power is subordinate to that enforcement mandate.