Switch, no. Try, sure. There are lots of ways to try Linux without throwing out the Windows box.
I have a laptop with Windows 7 and Linux dual boot. I need Windows for VPN into work, VS at home, Netflix, and games. If none of those things are needed, then I'm on the Linux side.
Alternately, I have a little headless Linux box with VNC setup. On a home network, with that old PC you don't know what to do with, this is an excellent choice. Set up a machine, get SSH on it, make sure it boots into Linux without anything plugged in, and stick it next the router and forget about it.
I usually plug external hard drives into the floating Linux boxen. I've been considering playing with a Rasberry Pi for this.