Microsoft is to release Windows 7 to customers worldwide on 22 October. At the same time the company will offer an upgrade service called the Windows Upgrade Option to current Windows users, Microsoft said.

The compaby had already said both the consumer and business versions of Windows 7 will be available in time for the year-end. A release candidate of the operating system has already been distributed through the Microsoft update service and has gotten generally positive reviews by users.

Windows 7 is the follow up to Windows Vista, which overall has been a disappointment for Microsoft and not very popular with business users or consumers.

Microsoft has said all versions of Windows 7 will run on PCs and notebooks as well as increasingly popular netbooks, which currently are running either Windows XP or Linux because Vista's hardware footprint was too big to run reliably on them.