The single biggest reason for existing laptop owners to upgrade to Windows 7 is something unique to this release: it actually requires less horsepower than Vista. That's good news for netbook owners!
This isn't just clever marketing. For the first time ever in our experience, you can give a laptop struggling to run an older version of Windows a new lease of life simply by installing a later OS.
The most obvious immediate impact of this is going to be for netbooks and we expect Windows 7 to quickly become the dominant OS here.
However, as the 1.6GHz Intel Atom processors that usually run netbooks are roughly equivalent in power to a Pentium M, a typical processor found inside laptops bought five years ago, it's very possible that your ageing Windows XP laptop will be able to run Windows 7 too.
It will cost you nothing to find out. Download the Release Candidate or install it from our disc and you can dual-boot Windows XP and Windows 7.
For Vista laptops, the effect is more impressive. For example, PC Authority's editor uses an ageing ThinkPad X60 with a 1.83GHz dual-core Intel Core 2 Duo T2400 processor and 1.5GB of RAM. Vista was usable but sluggish. Installing Windows 7 brought a noticeably fresh spring to its step.
Also in our series, Windows 7 the complete guide:
Part 8: Hunting down those missing files
Part 7: Good news for gamers?
Part 6: Blu-Ray and displays
Part 5: The new XP mode
Part 4: Playing DivX and XviD files
Part 3: Will your PC actually boot any quicker?
Part 2: Raw performance benchmarks
Part 1: Good news for gamers?
Also see: The 30 Best Features of Windows 7