If Microsoft made cars, the joke goes, they would crash twice a day, need regular upgrades and have to be replaced every time the lines on the roads were repainted.
But Microsoft does not regard car software as a subject for jest. Last week the software giant demonstrated the first production cars, Fiats and Alfa Romeos, running the full version of Windows Mobile for Automotive at the Geneva motor show. Tomorrow it will show off a Volkswagen concept car offering full internet access at the CeBIT technology exhibition in Hanover.
The car is the latest battleground for control of the operating system. Microsoft Windows already has a near-monopoly on desktop PCs, and the company has since assaulted markets for servers, mobile telephones and portable digital assistants. Using a cut-down version of Windows, the company is also providing the operating systems for television set-top boxes and manufacturing equipment, including robots in car factories.
"What we are looking at really is the car as a mobile PC," says Manuel Simas, European automotive business development manager at Microsoft. "The way we see it, the driver is just a driver but everyone else is either in the home or office. It is about the digital lifestyle and integration between the car, office and home."
In the push to make its products ubiquitous, Microsoft is aiming for control of the operating system for the car's "infotainment" systems - the technology that controls music, satellite navigation and even mobile phone connections. Last week's launch of three Fiat cars running Windows was the first step in introducing the brand to drivers, and Microsoft says at least one other carmaker is poised to follow.
"This market is still at a formative stage," says Dan Benjamin, transportation analyst at ABI Research. "This generation of products is going to be a major test for Microsoft, who have to prove their reliability and ease of development."
Customers opting for Fiat's Blue & Me system, a version of Windows, will get the first cars with a factory-installed USB port, allowing almost any music player to be plugged in. They will also get a wireless Bluetooth link, allowing hands-free use of most mobile phones.
Navigation connections, allowing external mapping devices or built-in navigation, will be offered soon. Music, telephony and navigation will all be voice-controlled, so drivers will not have to fiddle with their iPod to change tracks.
Giuseppe Bonollo, who oversaw the development of the system for Fiat, says the low price - €220 to €300 for the music and Bluetooth link - should boost take-up. He hopes to get 10 to 15 per cent of customers to opt for Blue & Me, against less than 5 per cent currently taking Fiat's factory-fitted hands-free kits.
He says having Microsoft's branding on the dashboard screen and the Windows logo on a button on the steering wheel is a positive advantage for Fiat. "We are delighted to be in a position to communicate to our customers that we were the first with Microsoft," he says.
But it remains unclear whether Microsoft will be able to convince many carmakers to give up their branding on the car operating system, something all have insisted on until now.In the long run, selling additional software to drivers offers the biggest opportunity in the automotive area, says Mr Simas, with the licensing of the operating system not a big money-spinner. He believes that when today's teenagers buy their first car they will insist on connectivity with their home equipment and personal digital assistant, and will want to run programmes they are familiar with, such as Microsoft's Office suite.
However, it is difficult for Microsoft to exploit its advantage because carmakers have so far been unwilling to risk letting drivers install their own software.
Manufacturers have maintained a strict separation between the infotainment software and critical functions such as brakes or airbags, but still believe any software problems visible to the customer would undermine their image.
"After some of the fiascos like iDrive [BMW's much criticised infotainment system] and pushing the electronics too far at Mercedes, they are likely to be a lot more conservative in future," says Mr Benjamin.