Pat Pilcher: Windows XP support ending, should we be worried?
Linux's open source price tag may be attractive, and there are other benefits besides cost. For a start, Linux is less of a resource hog than other platforms, and it works well on older hardware, especially compared to Windows.
Linux is also highly customizable, and users can choose from a multitude of desktop environments, such as KDE and GNOME. Going down the Linux route is however likely to involve a steep learning curve for non-techie users, who'll also have to sort out apps and drivers for legacy peripherals (or replace them with Linux-compatible equivalents).
Then there's support. It may be a non-issue if you manage to find replacement apps and drivers for peripherals. This said, almost that everything you're ever likely to need to know about whatever flavour of Linux you decide on can be found online, but once again isn't a terribly user friendly experience for Linux novices.
Another alternative is Chrome OS. Developed by Google, Chrome OS is web-centric operating system, which means that the browser becomes the operating system. Because of this there's far fewer security issues than with Windows as Chrome OS doesn't run locally installed software so there's little to exploit.