This is one of the longer posts I've made regarding Linux's viability as a Windows replacement. I've edited it a bit from the original for things that have changed since then:

Linux is a toy. A powerful toy. An-almost-infinitely-customizable toy. But a toy nonetheless. I say this because the people who use it do so because they enjoy fiddling around with config files. Even if they actually like using it--and of course they do--using it requires one to fiddle with config files in ways that one would only know how to do if he enjoyed learning about such things. I'm sorry, but that is a tiny subset of the computer-using public. Most people don't want to fiddle with things to get them to work or use weird, off-brand knockoff software developed by groups of people who do it as a hobby. It is a toy.

Invariably, this comment upsets a lot of people and there's the obligatory "It runs the internet!" and "dont be rediculous i use it for my business!" (sic) replies. But none of that means it's not a toy. OpenOffice or Crossover Office do not a real computer--as most people actually use them--make. Most businesses do more than type and make spreadsheets.

Here is a quick list of software my parents' company, for whom I do IT from time to time, uses. These are industry-standard applications:

PowerClaim [powerclaim.com]

Xactimate [exactimate.com]

Internet Explorer (for dealing with the head office)

Without these, their business does not run.

Another repost. I have intimated on this site before my thoughts on Linux, and have always wanted to write a monster post that details them more thoroughly, but the time doesn't come. Here is a slightly-edited-for-readability post from elsewhere on non-computer-savvy people's ability to set up and use Ubuntu Linux:

I build my own PCs. I think that's falling-off-a-log easy. But try to get a noob friend of yours into it. No really, try. They'll come up with the goofiest, craziest, hardest questions you've ever heard. I understand on a conceptual, top-down level what is going on when I'm putting a system together and getting drivers, etc. I've been doing it long enough that when I build a new one, it's a simple matter of just learning the changes since last time I did it. Usually I already know about them because I'm a geek and keep up on such things for fun. But, for example, the change from 20-pin to 24-pin ATX connectors caught me completely by surprise and required another trip to the store to get an adapter. It still happens. I know to look up beep codes. I know what to do if it doesn't start up. When all is said and done, I forget these little problems because they are not memorable--they are not salient events because I calmly and quickly solved them. This is not the case to a person who doesn't have that comparatively vast storehouse of latent knowledge.

For someone just starting out, though, that "24-pin ATX connector" confusion happens with every single step of the process. What seems simple to us only seems that way because we've got a massive backlog of understanding that we just take for granted. We only need to make adjustments to it.