Windows 8 will be out in around two years, according to a Microsoft blog on the Redmond giant's Dutch website.
Microsoft told IT PRO it had no comment on the leak at the time of publication.
The blog, as cited by Winrumors.com, said "it will take about two years" until Windows 8 is on the market.
The news came just days after Microsoft celebrated the first birthday of Windows 7.
Microsoft said nothing of the next Windows incarnation on the anniversary, instead stressing the importance of improving its most recent operating system.
"Users have more choices than they ever have, which is great, but it means we have to work harder for our share of voice out on the market than we've ever had to before," said Gavriella Schuster, general manager of Windows Product Management.
"But I still think people are pretty excited about it."
Microsoft has sold over 240 million Windows 7 licenses since the OS was launched.
Migrating over
As for the migration process for businesses, many have experienced delays in moving over from XP and Vista to Windows 7, Symantec-commissioned research has indicated.
Most of the 1,360 IT managers surveyed said migration took longer than expected, with 52 per cent citing application incompatibility as the chief reason for delays in deployment.
Martin Hill, EMEA sales director at Dell Education Services, stressed that firms "can't just flick a switch" when migrating from one OS to another, and they need to address "significant" skills gaps when shifting workers over to Windows 7.
"Even if it is a small business, there will still be a detrimental impact from switching in one way or another," he told IT PRO.
"That's why we've been evangelising about tackling the skills gap."
Firms need to plan the most effective way to migrate without experiencing excessive downtime, Hill added.
If Windows 8 is coming in two years, firms may have to plan sooner rather than later.
