Hull had a chance midway through the first half as the ball fell to Fraizer Campbell just outside the box, but his tame half-volley went straight into the arms of Ian Bennett.
Sheffield United took the lead on 35 minutes as Alan Quinn slipped the ball through to Stead with space and the ex-Premiership man calmly slotted the ball through the legs of Boaz Myhill from ten yards.
The home side levelled the scores in the second half via the penalty spot after Michael Tonge had brought down Campbell in the box on 55 minutes. Windass took the penalty and scored with ease as he sent Bennett the wrong way.
Ian Ashbee nearly had his side in front moments later as Windass laid the ball off to the Hull skipper whose fierce shot from the edge of the box was well turned away by Bennett.
Campbell had a great chance to put Hull in the lead midway through the half as Bryan Hughes swung in a pin-point cross into the area, but the Manchester United loanee could only glance the ball wide of the mark.
The Tigers came even closer moments later as Damien Delaney managed to cross the ball into the box from the right with Windass flicking it on to Richard Garcia, whose header from close range clattered against the crossbar allowing the Sheffield United defence to clear the danger.
Delaney came to Hull's rescue in the last ten minutes as Danny Webber weaved his way into the box and played a neat ball right across the six-yard box from the left, but the big Irishman raced in to intercept and cleared the danger for the home side.