External floppies are required by XP for setting up networks, for rescue, sometimes for other ad hoc things. Oddly enough, they are also sometimes required by major Linux distros I've encountered like OpenSuse, Gentoo, CentOS (maybe older versions, I don'nt know). So how do you get one? Are they expensive?
Cheap and tested (I own three), here:
I got mine several years back for $5 each, so the price here is good. Some in Amazon sell for much more, tub the point is, you hook them up with a standard mini-usb cable; you'll already have one of these if you had the prior-generation smartphones (like the Razor). Just hook the cable into the usb and at the side of the floppy drive, and you're ready to go. Works in XP, 7, 8, 10, and in Linux.
As I type I'm using that floppy to cause one of my XP machines to set up a network, now that I've newly resurrected the drive that was in my HP machine, into a Dell 6510 (don't ask, took two weeks, still don't have the right sound drivers).