Maybe the "accumulated junk from uninstalling software" is an acccepted response on a Windows PC forum.
Ereaders are linux or Android, have set software, no registry, and anyway have a much better OS and software management model.
The only thing reinstalling my computer could possibly accomplish is requiring me to reconfigure the entire system to have the same installed software and in-use configuration as before... until I have an identical filesystem to the on I rashly deleted.
So I assume the same goes for my ereader.