Windows Anytime Upgrade is an initiative from Microsoft designed to enable customer to upgrade their edition of Windows Vista. Via this option, users will have easy access to higher-grade editions for Windows Vista from their existing edition after completing an online transaction.

"For example, if a Windows Vista Home Premium or Windows Vista Business user decides he or she wants more capability - perhaps to join his home PCs to secure domains at the office, or to experience the multimedia capabilities of Windows Vista on his work laptop - Windows Anytime Upgrade makes the process of moving to Windows Vista Ultimate expedient and affordable," revealed Microsoft.

Possessors of a Windows Vista DVD will be able to purchase online a digital key that will unlock a higher-grade edition of the operating system, simply by accessing the Windows Anytime Upgrade option in the Start menu.

"Within Windows Anytime Upgrade, customers will be able to obtain detailed feature-by-feature information on the different Windows Vista editions, so that they can make an informed decision on whether an upgrade is right for them. The integrated desktop and e-commerce experience allows customers, with one click, to go from the Windows desktop to an e-commerce shopping cart containing the upgrade path they have selected," added Microsoft.

Windows Anytime Upgrade is a unique business model, and users will be able to buy higher-grade editions from Microsoft or from a select group of original equipment manufacturers.

"Come 30 January, Windows Anytime Upgrade will allow customers to purchase and download a digital key to upgrade to a more feature-rich edition of Windows Vista. The user will then complete the upgrade process by inserting the Windows Vista DVD that came with their PC or with their retail purchase of Windows Vista. The program will be available in the US, Canada, Europe and Japan," revealed Nick White, Microsoft Product Manager.

Here are Microsoft's suggested retail upgrade prices for Windows Vista:

- Home Basic to Home Premium $79,
- Home Basic to Ultimate $199,
- Home Premium to Ultimate $159,
- Business to Ultimate $139.