Windass' double and two strikes from midfield playmaker Marc Bridge-Wilkinson saw the Bantams storm into a four-goal lead by half-time and Martin Allen's men had no response to the onslaught.
City boss Colin Todd had urged his players to end their season on a high, despite having little but pride to play for, and they responded superbly against a Brentford outfit who had seen their own play-off hopes boosted by a four-game unbeaten run.
Windass went into the game needing two goals to match his best ever return of 24 in a season and his golden boots should have put the visitors defence on red alert.
But after just six minutes he managed to spring the offside trap and, after calmly controlling a cross on his thigh, he coolly lifted his chip over stranded keeper Stuart Nelson.
With the pressure off them the City players ripped into Allen's men and it was no surprise when the Bantams extended their lead. Bridge-Wilkinson had shown his willingness to get forward early on and after 23 minutes he struck a superb 20-yard shot beyond Nelson.
A minute later referee Kevin Wright waved away a strong Bradford penalty appeal and Brentford were unlucky not to pull a goal back when striker Scott Fitzgerald's close range effort was ruled out for offside.
Jamaican international keeper Donovan Ricketts marked his City debut with a superb fingertip save to push away Deon Burton's long range strike and, after 36 minutes, Windass was on target again with another smart finish.
Bridge-Wilkinson picked out the front man with a slide-rule pass and Windass kept his head to chip a right-foot shot over Nelson from 12 yards.
As City surged forward Windass headed wide, but in injury time at the end of the half Ricketts sparked the move of the match with a superb throw-out.
Winger Ben Muirhead sprinted upfield and when his right-wing cross came into the Brentford box Windass' step-over allowed Bridge-Wilkinson to fire a right-foot shot home from 10 yards.
Allen responded to the setback by making three substitutions at half-time but, despite having more of the play, his men still struggled to carve out any clear-cut chances.
Windass had a header ruled out for offside and wasted another great chance late on while his strike partner Andy Cooke somehow managed to miss with a free header inside the six-yard box.
Ten minutes from time Brentford substitute Jay Tabb was rewarded for his persistence in the box when he fired in a consolation goal despite David Wetherall's attempt to clear the ball off the line.