Agreed, a lot of it does depend upon the disk. Yet a lot of it also depends upon licensing. Linux distributions can afford to include virtually all of the available drivers and applications because the dominant licensing schemes permit it. Microsoft cannot do so unless they have the rights to do so, which means negotiating with third parties or sticking to the standards. The competitive nature of the commercial marketplace also creates headaches. Microsoft is not going to ship Windows with LibreOffice because it competes with their own office suite. Microsoft probably wouldn't get away with shipping Windows with their own office suite because it would be deemed as anti-competitive.

This spills over into other areas too. As an example: while Ubuntu ships with LibreOffice, they don't have any issues with including competing office suites in their package manager. Stuff like that makes Linux distributions a lot easier to use and maintain because the end user has control rather than the vendor.

Windows itself though is awfully temperamental. You mentioned things like having the right disk, which is often hard to come by because of copyright and licensing issues. Historically you could update your disk by slipstreaming, which was beyond the average user. Thankfully it looks like Windows 8 has started to address that issue by applying updates to USB installation media. Inconsistent installation processes are likely addressed by Microsoft's Store, yet that's nowhere near as comprehensive as Apple's Mac App Store (never mind the package manager of large Linux distributions).

I think the best way to summarize the difference between Linux and Windows in this respect is that Windows is uniformly difficult. With a decent Linux distribution, things are either super easy or super hard. That is to say, a Linux distribution that does what you need of it out of the box is significantly easier to deal with than Windows. The problems pop up when you ask it to do something out of the box, at which point things will become incomprehensible to most users. Whether you fall inside or outside of the box depends upon the needs of the user and the hardware that they own. Someone who does almost everything through a web browser, uses standard productivity and creativity applications, as well as well supported peripherals is not going to run into many problems with a distribution like Ubuntu. Someone who needs to use a particular application, wants access to bleeding edge features, or buys lots of poorly supported hardware is going to feel like gouging their brain out with a toothpick if they try any Linux distribution.