The slogan for Microsoft's £139m marketing blitz to launch the Windows XP software has been scrapped in the wake of the US terrorist attacks.

"Prepare to fly" was deemed to be inappropriate after the September 11 atrocities and will be replaced with "Yes you can" for next week's launch.

Stephanie Ferguson, Microsoft's PC experience marketing director, confirmed that some changes had been made.

But the ads, made by Microsoft's agency, McCann-Erickson, still feature people soaring over fields and through offices echoing the flying theme.

A spectacular launch party in New York on October 25 will go ahead after Bill Gates, the chairman of Microsoft, consulted the city's mayor, Rudy Giuliani, about whether to cancel the event.

The company is spending £139m over just four months to launch Windows XP. A large chunk of the money will have gone to Madonna, whose hit Ray of Light will be the campaign's theme tune.

Apart from TV commercials, Microsoft will also roll out print ads in magazines and newspapers, online banner ads and billboards in major cities.

The ads feature the XP's signature look, which Microsoft refers to as the "bliss screen" - a bright blue sky with cottony white clouds and a green field.

Other marketing activities will include 62 launch events around the world, expected to reach an estimated 100,000 people, and the distribution of 11m CDs containing demonstrations of XP features in stores and with magazines.

When Windows 95 launched six years ago, people lined up at midnight to buy up the first copies. But XP is being launched in difficult times for the computer industry.

Microsoft and its partners, including Intel and Dell Computers, had planned to spend $1bn (£694m) on global advertising and marketing. But the budget was reduced in light of the slowdown that has hit the industry.