Windows 7: How low can you go?

Linux has long been the preferred operating system for rejuvenating older PCs for three reasons: It's lighter weight than Windows, it's secure enough to let you sidestep CPU-hogging anti-virus programs, and it's free.

Windows 7 may shake up that thinking, being the first version of Windows that, judging from widespread reviews from beta testers, runs faster than the prior one. While the minimum specs Microsoft outlined for Vista were lower than Windows 7's (see breakout box), Vista was so bloated that it ran poorly on many PCs. Think of Windows 7 as Vista after an extended stay at the weight-loss spa -- trim, buffed and Botoxed. Even netbooks can run it.

In the past it usually made little economic sense to reinstall Windows on an older PC, as buying a new retail copy of Windows would often cost more than the PC was worth. But with Windows 7, Microsoft plans to offer a 3-upgrade-license 'family pack' of the Home Premium edition for $150. Based on what Microsoft has already said, users will likely be able to (clean) install Windows 7 on a machine running XP without having to install Vista first.

Also, Windows 7 continues Microsoft's legendary backward compatibility for applications. For instance, I was able to get my 12-year-old copy of Office 97 running on Windows 7 with no hitches.

But just how low can you go with Windows 7? Do you really need a computer with the minimum specs as outlined by Microsoft?

Like lo-fi DJs and classic car enthusiasts, a subculture of Windows fans has sprung up trying to take Windows 7 far lower than Microsoft says it can go. At Windows fan site Neowin.net, testers have claimed success with a 700MHz Pentium III ThinkPad with 256MB of RAM and a 600MHz Pentium III desktop with 512MB of RAM.

At another site, The Windows Club, someone claims to have run Windows 7 on a circa-1997, 266MHz Pentium II with 96MB RAM and a 4MB video card.

While not matching those reports, the following five accounts are from users -- including yours truly -- who have successfully run Windows 7 Ultimate RC on a variety of older and underpowered hardware, from a 7-year-old white-box desktop to a Dell netbook. All the testers weigh in on their Windows 7 experience and provide tips for installing it on low-end systems.

Sprucing up the old work laptop

Who: Jan Andersen Cornelius, a technology architect in Roskilde, Denmark

What: "Several laptops, including a Dell Latitude D600 and a ThinkPad T60. The oldest was my Asus L3800c that I used [when I was] an independent consultant between June 2002 and April 2004."

Specs (Asus): 1.8GHz Pentium M CPU, 1GB RAM, 160GB hard drive (5,400rpm), ATI Mobility Radeon 7500 on-board graphics

Windows Experience Index (Asus): 1.0

[Note: The Windows Experience Index is a set of 5 scores on a scale of 1.0 (lowest) to 7.9 (highest) that are generated by Windows 7 based on your PC's hardware specs (not how it actually runs). Microsoft bases the overall rating on your hardware's lowest individual score.]

Performance: On the Asus machine, it's "a little bit slower than Windows XP (I'm running both in dual-boot) and Office 2007. It takes a while for everything, including Java, to start up. On my Dell, it is a lot faster than Windows 2000. Same with the ThinkPad when compared to Vista."

Would you recommend Windows 7? "Personally, I would not hesitate to install Windows 7 on any machine built in 2003 and after."

Tip: "Make sure you install the 64-bit version if your hardware supports it. It will be a lot faster."