"Our aspirations are probably higher than they were a year ago," declared Frank Williams, whose team finished 2003 as overall runners-up to Ferrari after looking like championship-winners at mid-season.
Williams said he would be disappointed if the BMW-powered team were not first at the end of the year and hailed his drivers as potential champions.
Montoya has already signed a contract to join McLaren in 2005 but the Colombian said that would have no bearing on his determination.
"I'm 100 percent committed as a Williams driver," he insisted. "We have a realistic chance of winning the championships and neither they nor I want to throw it away.
"I want to win, we're here to win. Simple. And I will do whatever I can."
Williams agreed with the driver's self-assessment: "His replacement is a problem for 2005 but I have no doubt about his commitment for 2004," he said. "He is a born racer."
RADICAL SOLUTION
The team have not won a Formula One title since Canadian Jacques Villeneuve in 1997 and the new season is set to kick off in March with Ferrari's Michael Schumacher the only man on the starting grid to have won the championship.
The new FW26 did not disappoint when it
The twin-keeled front end was a radical departure from previous aerodynamic solutions, strikingly different with the nose cut short and the front wing jutting out from it.
"We've eliminated the part of the nose above the front wing, and it allows more freedom for airflow over and below the car," said technical director Patrick Head.
While McLaren had their new car running at the end of last year, Williams are the first team to hold a formal launch for their 2004 challenger with Ferrari not due to unveil theirs until the end of January.
"Looking back on 2003, we realised we had not left ourselves enough time before the start of the season," said Head explaining the comparatively early launch.
Williams made a slow start to 2003, their car jokingly compared to a tortoise before it showed its true pace when Montoya won at Monaco in June and Ralf then triumphed at the Nuerburgring and France.
Montoya also won in Germany in August.
"I think the car is a fairly logical development within the rules but there are one or two aspects that look slightly different," said Head.
"The ambition for Williams is to do something we haven't since 1997. This is the longest period in Williams' history without a championship. Our target is quite clearly both championships."