Winows XP It may have taken eight years, but Microsoft has finally finished its replacement for Windows XP. Yes, you read that right: XP.

The company thought it had the job cracked when Vista - or Windows 6.0 - launched in 2007, but the world begged to differ. Users complained that Vista was slow and even more unwieldy than the operating system (OS) it was supposed to replace.

Many XP users chose to skip a generation and wait for Windows 7, which even Microsoft has quietly ‘code versioned' as Windows 6.1. And Windows 7 is worth the fanfares: it runs smoother than Vista, and has even toned down those tedious User Account Control (UAC) notifications a little. After being hurt in the pocket and ego, Microsoft has started listening to its audience, and Windows 7 is a great step forward.

Windows 7 review

Windows Vista review

With all the latest Windows laptops and desktop PCs moving to the new OS, you can be sure we'll be testing them as thoroughly as ever in the PC Advisor Test Centre. Our lab is prepared to take on every new PC, gauging its performance with a suite of benchmark tests that enable us to make fair comparisons.

As laptops and netbooks gain even higher ascendency over deskbound PCs, it's more important than ever to check genuine battery life. We'll continue to publish realistic run-time figures using the industry-standard BapCo MobileMark 2007.

Mac OS X 10.6 Snow Leopard review

Desktop PC reviews

To check real-world PC speed we use WorldBench 6 Gold, now out of beta and ready to give Windows XP, Vista and 7 systems an exhaustive workout using real programs such as Excel, Photoshop and Windows Media Encoder. Importantly, scores awarded with the latest version of WorldBench are comparable to those you've seen in print for the past few years. And expect to see new systems nudge their scores higher, an indication of Windows 7's improved speed credentials.

The other newsflash of late 2009 is the (early) arrival of Apple's Snow Leopard OS. Mac OS X first went public in early 2001, the same year as Windows XP, and has steadily become quicker, slicker and more robust with each version upgrade. Apple has increased its Mac market share in that time, an achievement that's had as much to do with Mac OS X's virus- and stress-free computing experience as the halo effect of the iPod and iPhone.