- Don’t display every name of a the file that is copied or any other process description, nobody can grasp them and effectively nobody cares.
- Don’t present percentage information or a bar reflecting the progress the installer makes, try to reflect the time it will take to finish the process. If you can’t, admit it, and present a simple progress indicator with no relation (anything that animates will do it) and show a message like “usually the installation takes around [put a number here] minutes to complete”, so that users can plan their time! A very rough estimation based on the installed processor / harddrive should be fine. Provide installation progress information only on request. A tooltip over the progress animation should satisfy the impatient.
- Never interrupt the progress for non-fatal user interaction, present all the dialogs you need in advance, test if the folders can be created, and so on. If you can’t, redesign.
- Don’t present “generating installer script” or other useless information as an excuse. Geeks know that if this is taking longer then a fraction of a second on modern computers without any drive access, you used an unscalable O(n ^ put your exponent here) algorithm somewhere.
- Use one single progress indicator and time estimation. Don’t present one for each module or installation pass. A progress bar going full and back to zero makes your users nuts.
And finally: Accept that installation and uninstallation should be one single transaction and so they should be presented. Optimize for speed and simplicity, that is the first impression you should give to your users. Don’t be proud of all the code, graphics, presentations, animations and computations you’ve created to make it look good. Instead, be aware that an installer effectively steals the most valuable thing in the world, and that’s time.
yours
armin
p.s.: I’ve written this text after I have destroyed my VS 2005 installation by uninstalling VS 2008 Beta 1. That problem was predicted by the readme file, but sadly the repair module of the installer showed nearly all the bad symptoms described above and was not even able to finish its job. Right now I am trying to reinstall VS 2005.