It's getting a little old hearing that Linux users make up a small...VERY small fraction of all personal computer users. I don't believe the numbers, which are typically put around 2%, and I'll tell you why.
1) Up until very recently, 99.99% [that's a guess, but it's probably reasonably accurate] of personal computers shipped with Microsoft products preinstalled, including Windows as the operating system. That meant that people like me--who wouldn't be caught dead using Micro$oft products--who wanted to buy a certain computer for its features would go ahead and buy it, then immediately wipe windoze off its drive, install Linux ourselves, and be on our merry way of computer-using bliss. So guess what that sale counted as? Guess what *WE* counted as? Yep, WINDOWS USERS. Since the mid-1980s I've personally been responsible for purchasing hundreds of computers, both for my own use at home and in my [former] position at work. Each of those computers came with windoze (DOS before that) preinstalled on them; with each one, as soon as I got my hands on it I formatted its hard drive and installed Linux (UNIX before that). Every one of those computers counted in the scheme of things as "a Microsoft user," even though nothing could be further from the truth.
2) Although it's now possible to buy PCs with Linux preinstalled on them directly from [enlightened] manufacturers, such as HP, Dell, and others, many of us prefer to do it ourselves. I've never had anyone else install *nix for me, and I can't imagine starting now. I like to take a blank, freshly formatted hard drive and build it from the ground up. *I* want to decide how to partition it. I have a very specific scheme I use for all my installations: I allocate a certain [small] percentage of the drive for its / [root] partition, a large percentage for its /home partition, a larger percentage for its /data [a common storage area for all users] partition, and a relatively small area for swap space. I don't want someone else deciding for me how to allocate space. And I have a specific way of installing the OS and applications, too. So if it comes down to wanting a new computer and the one I like happens to have windows on it, I'll buy it, wipe it, install Linux and proceed as usual. And, once again, the records will show that I'm a Windows user. NOT!
3) Many people who want to "get their feet wet" with Linux, but aren't ready to fully take the plunge, start out by dual-booting Linux and Windows. Once again the computers they're doing this on were sold with Windows preinstalled on them; once the user got the computer home and decided to try Linux, they set up a dual-boot arrangement which the computer manufacturer or retail store knows absolutely nothing about. So, once again, this person goes into the books as a Windows user.
4) Another way that people use Linux is via virtual machines. With products like VMWare they can run Linux inside Windows and--you guessed it!--the computer was counted as a Windows computer when it sold.
See where I'm going? It's not as cut and dry as the Linux hating pundits like to imply.
On a related note--misinformation from Linux hating pundits--it's simply not true that there's no help available if you're stuck and need assistance. Unlike Micro$oft where, like EVERYTHING related to M$, it costs $$$ for support, in the Linux world just ask and you shall receive. There are many Linux forums/message boards, some devoted to specific distributions, such as Ubuntu, and others to Linux in general, as well as many Usenet Linux groups. Plus IRC if you're into that. If you're having a problem with Linux and you can't find the help you need online...you're doing something wrong. There are simply too many places and too many people willing to help that anyone should be left hanging.
In summary, the numbers commonly used to represent the percentage of PCs running Linux are inherently flawed, and if you need help using Linux, all you have to do is ask.