I started doing my Rails development on a Windows machine. It was painful; the Rails community just doesn’t care much about Windows, so simple things like running a MySQL database were frustrating to get working. Many other little things wouldn’t “just work” and I’d waste time trying to decipher setup issues instead of coding. Particular problems will get fixed over time, but Windows support will always be a few months behind, so Windows Rails developments will always run into more glitches.
Also, running unit tests (a must!) on Windows was extremely slow. It would take me almost a minute to run a test case, even after fixing a tiny syntax error; this kills productivity and may even push you to write sloppy, untested code. Now I’ve got it running in about a second on Ubuntu Linux. It’s a massive difference and it makes me a better developer.
So I switched to Ubuntu, and you should too. The learning curve is surprisingly short; your favourite Ctrl-C Ctrl-V shortcuts will work out of the box, and installing programs isn’t that bad. You don’t need to use vi or emacs. I’ve got it dual-booting, so Windows is still there if I need Microsoft Office or other Windows-only programs. Mac is good too; a colleague is dual-booting Windows 7 onto a Macbook Air and loves it.
If you’re still afraid of learning Unix, consider that you’re crippling your options for deploying your apps. You’ll be a better developer by becoming comfortable in a Unix environment, so you might as well do it now.
If you’re doing Rails development and you’re using Windows, do yourself a favour and switch operating systems. You can try Ubuntu for free, so what are you waiting for?