Why? The "average computer user" is precisely the kind of person who is likely to have commodity hardware that is supported by Ubuntu. Would you not recommend it because you can't guarantee that Ubuntu will work with all her hardware? If that's the problem, then what would you recommend? Can you guarantee that some other OS supports every piece of hardware she owns? Or are you holding Ubuntu to a higher standard?

If the answer is simply that you believe another OS will support more (though maybe not all) of her hardware, why not at least recommend that she get a Live CD, try it and see? Then she can weigh for herself the benefits of a (mostly) Free software OS against the extra cost of getting her hardware to work, instead of just accepting your guess that it's not worth it.

Because the average user just wants his computer to work, he doesn't want to try something unfamiliar and risk doing even more work to get the computer working. Maybe we don't have the same definition for "average user".

Hardware can be expected to work on Windows. If they don't, it's the hardware manufacturer's fault. There might be nothing you can do about it, but it's their fault. They manufacturers are expected to support Windows. If hardware doesn't work on Ubuntu, it's your fault for installing an unsupported system.

> Hardware can be expected to work on Windows. If they don't, it's the hardware manufacturer's fault.

Sorry, this is an unreasonable expectation, and one that should be corrected, not reinforced. The "average user" has no right to expect that an operating system should work with any and all hardware, simply because one operating system has a monopoly position with respect to users and a monopsony-ish position with respect to hardware makers. It hurts all computer users, and Free software users in particular, when we allow such companies to set our expectations.

Who is this "average computer user"? Anybody that makes the jump to Linux has a reason to(and there many, not just tinkerers), otherwise they stick with a windows machine or pony up for a mac.