Le’ts say, you want to inform your user about what’s going on (which is a nice thing to do).
This is an example of how not to do it:
What exactly is that “RemoveTempHxDs”, the installer is doing right there? And why is the progress bar at 100% for more than three minutes when I made the screenshot?
If you are unable to provide meaningful progress information, don’t provide it at all. Make your program display a “neutral” progress bar (some spinning wheel or something like that) and make it tell the user it’s “Doing stuff…”. Why expose useless internals?
While I see some value in displaying information like that if it’s to have more information when you are trying to support the application. But in that case, a log file of some kind is much more valuable as it both gives YOU as developer the information you need and does not confuse your user.