If you're planning on upgrading to Windows 7 soon, keep in mind that you'll need to upgrade your printer and scanner drivers as well. And that's not always easy to do, since those drivers may not exist yet --and may not be around for a while. That's according to Martin Heller of InfoWorld, in Windows 7's Spotty Driver Support. Heller checked for a Windows 7 driver for his HP Officejet Pro L7590 all-in-one and, while there is an entry for it on HP's download site, there's no actual driver for either the 32- or 64-bit versions of Windows 7. Instead, there's a "basic driver" workaround, that does allow basic printing, though HP warns that "some of the advanced product features are not available. " So before you upgrade, go to the Web site for any of your peripherals and make sure you'll still be able to use them in the way you need to.
Update (11-3-09): Jeremy Kirk of ComputerWorld writes that HP expects many drivers to be released soon. HP's Web site (check the tab at the top left for different HP printer and scanner lines) notes, somewhat alarmingly, that "If your legacy product is not listed, no support is offered for Windows 7."