I agree with Machine and Metal (it's a miracle) regarding Ubuntu / Linux usage.
I have a financial and engineering background and can confidently say that I've successfully installed and ran Ubuntu on all three on my home computers, despite using only Windows in the workplace. I only have one copy of Windows at home that I keep "just in case." For most PCs, transferring to Ubuntu is clean, quick, and easy. I only had moderate issues on one of my machines. So I'd say the average person who hasn't ever worked in the software industry can work it out
"I don't buy into the notion that Firefox is a better browser."
I don't either. Chrome is. To be serious however, a browser is only as good as its operating system. And Windows has been passed by Mac and completely overlapped by Ubuntu, in terms of safety and speed.
"Windows is great if you're low on money"
Ubuntu linux is open-source (perhaps why it appeals to guys like Metal and I), which means it is completely free to anyone and you can customize it anyway you please without worrying about copyright infringement, etc.
Now, I will admit that Windows 7 is a huge leap for Microsoft. But it still suffers from the same typical Microsoft issues: poor security, slow speeds, and high cost of operation.