>- installation that wants to install any toolbar anywhere
>- installation that wants to install anything but what it first said it was
>- installation that installs anything else without telling you
>
>On the highly annoying list:
>
>- doesn't offer a choice of folder where to install, goes for c:\program files
>- offers it only within custom install, but then doesn't give you a textbox to just paste a path you want, has only the folder tree.
>- when you change your mind and go back to the location page, the previous location is forgotten and you get to start from c:\program files again
>- comes in a self-extracting exe, which then unpacks into a temp folder, which then vanishes when done, but then it can't uninstall because it can't find the installation (msi is notorious of this).
>- keeps hundreds of megabytes of its unpacked install on your C: drive in some temp folder, then refuses to uninstall because you purged temp folders, so you have to keep it forever or scrub the registry if you want to get rid of it
>- has a readme which displays in a window no larger than Fox's expression builder, which can't be resized
>- calls home (.msi installs and particularly Chrome are notorious)

Thanks, those are interesting situations that we face from time to time. It is also a good list to verify for specific things when building install program for our development applications.