*Using* Linux with a GUI (Graphical User Interface like in Windows, you could also go without) isn't harder than windows, but different.
Examples: click your menu, click openoffice / firefox / whatever.
Use program.
So, you'll propably be familiar with the applications quickly. However, you'll notice differences of course.
The GUI will be different, but no matter which (major) one you use, like KDE or Gnome (preferred by me, used by Ubuntu by default) you'll be able to use it.
The other difference you'll come across is the directory structure. There are no drive letters.
So the root is not 'c:\' but just '/' wherein everything (even devices!) is contained. Your files and settings will be at '/home/yourname'.
As others pointed out, when stuff goes wrong it will be hard. Even I still google around for specific things and I routinely administer linux servers. However, going that far in windows is really hard, too, and solutions are often everything else but logical.
Now to the huge upside. If you know, or want to know, what you're doing you'll see a system far more consistent than windows. It does what you say. You do not have a bloated registry but simply files you can edit, save, restore (e.g. gui settings contained in home directory, or /etc for all settings of the os). But it's a steep learning curve if you want to get into that. I actually don't think the command line interface (mostly bash) is harder than in windows, but far more advanced. The things you can do there with just typing a line is the stuff dreams are made of.
So yeah, just try ubuntu. It'll most likely just boot up and you can start doing stuff. Give us a clue why it didn't work/boot from cd?