Dear Nicolas_695, Believe me, I totally understand your frustration and helplessness - I was on the same boat and even consider to bite the bullet and reinstall Windows. Unfortunately, I still don't understand what has happened (only Microsoft people may be able to find out - and I don't think they care). My problem began when the language pack I was using (in my case, Simplified Chinese) was acting strangely (mixed characters with traditional Chinese), so I thought uninstall and reinstall the language package could help - big mistake - it triggered the reported "never finished installation problems" since, which brought all of us, the victims, here.
When I read encouraging report from Yuan X about his successful experience, I was extremely excited - not I thought it would be easy, but because I knew it could be done.. Following his advice, I failed a few times, but eventually succeeded (can you image how happy I was - a monkey off my back). Since I don't know why the problem was to begin with, and why the fix worked for me finally, I really can't tell you what to do. The only thing I can pass on to you is that when I run "dism /online /cleanup-image /restorehealth" under CMD (must be in "administrator's mode"), it took a LONG time (hours) to finish (i.e., the control return to CMD prompt) - and that was the time it worked for me. Before this, I cut off the long "dism" run after I found it finished all the patches (by browsing the log) - I am not sure whether this is relevant, but those efforts to terminate prematurely failed.
I am sorry I can't be more precise than what I have offered (as in the "blind men and an elephant", we don't really know what the elephant really looks like). I can only ask you to try it a few more times, knowing some of your fellow victims have succeeded after all. If you decide to give it up, you can always do what I was planning to do as a last resort: to reinstall Windows with the option to retain all user files. You, however, will have to reinstall all apps (e.g., Chrome), and reconfigure all settings. Wish you the best of luck (and hope you will report your success back to the Forum later?) JP