Microsoft's Windows 7 becomes officially available from midnight tonight, and the firm is offering several inducements to persuade users to upgrade.

Microsoft extolled the virtues of Windows 7 at a London launch event today, saying that, following Vista, it had listened carefully to customers' needs and delivered them in the new platform.

"Windows 7 is more than just a collection of new features; it's a pivotal point in Microsoft history. It's about listening to users. People told us 'make it simple' and 'make it work the way I want it to', and that's what we've done, " said Ashley Highfield, vice president of consumer and online at Microsoft UK.

Microsoft UK's Leila Martine detailed some of the key enhancements in Windows 7, including longer battery life on laptops, and better security with the improvements in Internet Explorer 8 included with the new operating system.

One new offer is that, for a limited period, customers buying a new Windows 7 PC from a participating retail partner can get a second copy of the software at a discount, allowing them to upgrade an existing PC as well.

The offer applies to Windows 7 Home Premium, Professional or Ultimate, allowing users to buy a second copy of the same edition for £49.99, £99.99 or £119.99, respectively, between 22 October and 2 January.

Students can also upgrade to Windows 7 Home Premium or Windows 7 Professional for just £30.

More praise for the new platform came from Jeremy Fennell, category director for PC World and Dixons parent group DSG International, who said there had been "no need for hype" to drum up interest in Windows 7.

"When we ran our pre-order promotion, the reaction was phenomenal. We sold more copies in three weeks than Windows Vista sold in a whole year," he said. " From our point of view, it offers a better user experience, better battery life, and boots and shuts down faster."

Fennell also announced that, from tonight, customers trading in an old laptop will be able to get £100 off the price of a new Windows 7 system at PC World stores.

For those opting to upgrade a PC with Windows XP, Microsoft had few words of comfort, however. Explaining the decision not to support an in-place upgrade from XP to Windows 7 (a clean install is required), Martine said that it was just too problematic to guarantee that an upgrade would work on every XP system ever sold.

"Some of these PCs might be up to 10 years old, and we think those users will want to continue with XP until they buy a new PC," she said.

In addition, hardware has moved on since the days of XP, and Windows 7 is designed to make full use of new systems, Martine explained. "There a lot of advantages in getting a new PC," she said.

V3.co.uk is running a three-part in-depth review of Windows 7. Part 1 can be seen here.