One of the reasons Windows dominates the market is because the big dogs that release popular software (ie multimedia companies like games, music, art, etc.) are too afraid to move onto the Linux platform.
The second reason Windows dominates the market is the fact that nobody is willing to learn the better system, that is Linux. The trouble with the average electronics consumer is that he/she is unwilling to spend time to figure out his/her device before he runs off with it and loads it up with viruses. People like devices like iPods and iPhones because they are so simple to use: they don't need to read that darn-ol' instruction manual. They don't have to educate themselves about it's features and abilities: it's all there in one button, and it does everything they need it to do, no questions asked.
Now, this would be fine and great, but the trouble is: computers are complex, you do need to learn how to use them before you run off with them, and you must be responsible enough to maintain them and keep them from wearing down, or it will not function.
Now, I am definitely not in favor of trying to turn the PC into some kind of elitist tool that only trained experts can use: many times, simplicity is a good thing. (hence the large number of GUIs that have been developed on top of Linux) But too many companies like Apple and Microsoft like to project the idea that your computer is nothing more than a pile of bolts that does whatever you want it to do, no problem. Ok, they admit that viruses are trouble, but with their automatic "Defensive System" it's no problem... Really!
Like I said, computers are complex machines. Your manual (and the online community) is your warranty: use at your own risk.
The Linux community, unlike Apple and Microsoft, understands these things and the Open Source community actively produces great, free software that can help you run your computer efficiently and safely... If you take the time to learn it.
Yeah, change is a painful process that many people are just not willing to endure. But sometimes, change is for the good and unless you want to stay where you are, you have no choice but to work with it.
I cannot tell you how many times my Dad has had to re-setup our main Windows family machine. He would use the best firewall, and he even setup two outer firewalls, but year after year we got hit with viruses. Eventually the computer would just hit a point where it was unusable, and we would have to start the process all over again. We have many other internet enabled PCs in our house, all with Linux on them, and we've never had these problems. So just now my dad has finally made the switch on our "Windows" machine, and so far it has worked like a charm.
