If you're upgrading to a faster, stronger wireless router, don't chuck your older Wi-Fi box. With the magic of DD-WRT, you can turn your older wireless router into a range-expanding Wi-Fi repeater to cover everywhere you need a connection.

What You'll Need

• Compatible router: Grab that old-but-still-works router and flip it over. Get the model number off the label, and write down the MAC address, while you're at it—the locations for both, on a standard Linksys "blue box," are pictured above. Type the first few characters of your model number into DD-WRT's router database, and look for your model to pop up. If you get any kind of green "Yes" listed with your model, you're in the clear—even the most pared-down DD-WRT build, micro, supports the repeater function.

• Firmware files for your router: In that same router database, click on the line that relates to your router model, then grab all the files listed there. You may not end up using all of them, but once you've taken your router offline, even if it's not your main router, you'll want to have all your files available offline.

• Print-out of your instructions: There's a good chance, if you've got a fairly popular router, that you'll have access to specific router model instructions on the DD-WRT wiki. You'll usually see a link on the same page as your firmware files; if not, go ahead and search the wiki. If you don't have a printer, or hate wasting paper, use a print-to-PDF tool like doPDF or the Nitro PDF Reader for Windows, or the built-in PDF functions in Mac or Linux. The reason, again, is that you want to be prepared in case you lose internet connectivity on one or more routers during the flash process.

• Ethernet cable & computer with Ethernet port: Enough cable to comfortably reach from your computer to the router you're working on, and a computer without any networking problems that you know of.

• A pen and paper: The paper for notes, and the pen for both writing and pressing and holding down the reset button on your router.

• At least an hour's time, and patience: Instructions for most routers are laid out in step-by-step detail, with very specific instructions. Even so, you do not want to rush things, or load the wrong file at the wrong time. Doing so opens the potential for a "bricked" router, one that doesn't work and can't be accessed or set back to its default, factory-fresh state. That's not going to happen to the patient, cautious firmware flasher, though.