I went to install the Movies expansion pack today, and when I clicked "install" from the autoplay menu, I merely got the ominous Windows(tm) Error Tone(tm), with no other feedback.  Now, fortunately I was able to get it working by rooting around on the disc for the setup.exe, old school style, and that worked fine.  But wow, what a point of failure.  If you can't even install the game, with no error message, you have no possibility of tweaking your options, or even applying a patch.

Sadly, installation programs are also a common point of failure.  We had a huge number of problems with all the corner cases we had to deal with for AOM's installer, many of them revolving around having the right version of XML installed, or the right version of IE installed.  The IE issues were particularly thorny because they were different on the various flavors of older versions of Windows... Windows 98 "first edition" is different than the later releases of Windows 98.  Crazy stuff (and one of the reasons that it certainly simplifies things to support only more modern OSes now).

Nice installs are a huge reason that I find console gaming just plain easier than PC gaming.  I'm cautiously optimistic that Windows Vista will help that some; I know it's something that they are trying to focus on...