Frequent fliers whose laptops run out of juice right before their movie ends might want to upgrade to Windows 7, given claims the OS allows batteries to last longer thanks to some integration work Microsoft undertook with chipmaker Intel.

"Microsoft and Intel engineers were able to reduce power usage of a Windows 7 laptop nearly 20% over an identical laptop running Windows Vista SP2," wrote Joakim Lialias, Intel's Microsoft relationship manager, in a blog post Monday.

As a result, a typical laptop will run for more than an hour longer on batteries than a Vista laptop, said Lialias.

Microsoft and Intel achieved the power savings by focusing on key system areas. Windows 7 is designed to power down devices that are not in use, shut off buses where possible, and maintain Intel chips in Deep Power Down state for as long as practical, according to Lialias.

"That gained an additional 1.4 hours of battery life" on a test laptop, said Lialias. "Enough extra power to blow by the credits and see all of the special features" on a DVD, Lialias wrote.

Lialias said that achieving such synergies between operating system and chips was made easier by the fact that Intel and Microsoft were on similar timetables for releasing their most recent products.

"With Windows 7 and Intel's new Core processors rolling out at roughly the same time, the team saw the opportunity to really put rocket engines on PCs," wrote Lialias.

Vista, Windows 7's predecessor, was plagued by incompatibilities with numerous, third-party hardware products. That prompted Microsoft to put extra effort into partner relationships during Windows 7's development.

Beyond tighter integration with Intel chips, Windows 7 includes a feature called Device Stage that automatically recognizes the make and model of peripherals that are added to a PC and allows users to manage the device from the desktop.

Microsoft formally released Windows 7 to the public last week. The company's promise to frustrated Vista users was that Windows 7 offers a more streamlined interface, improved compatibility with third-party hardware and software, and less intrusive security measures.

The full version of Windows 7 Professional is $299, with upgrades going for $199. Windows 7 Ultimate is priced at $319, with the upgrade version at $219. The full version of Windows 7 Home Premium is priced at $199, with an upgrade from Vista or XP selling for $119.