This will have an impact on the computer industry as it's not optimal to launch a new operating system right after the holiday season:
The world market is largely driven by demand in Europe and the US, and that demand is dependant on innovation to make people buy new models of computers.The primary reason for the delay are measures to improve security.
Most computer sales also take place in the crucial fourth quarter period which covers Christmas.
"The industry had been expecting Vista to arrive in time for the important holiday season at the end of the year," says Brian Gammage, research vice-president at technology analysts Gartner.
"This means they don't have the new system in place in new computers for consumers. The impact for the industry will be a disappointing one."