On my laptop, the lockscreen is completely blurry. Has anyone ever had experience with it and how can I get rid of it?
The dilemma came with the last major feature update, I solved the problem with the following page: https://www.windows-faq.de/2019/06/04/unscharfen-oder-verschwommenen-windows-10-anmeldebildschirm-wieder-scharf-darstellen/
I have the problem that the password input does not exist
Oha, that's a whole other problem. With good luck, a cold start of the system would help after pulling the power for a few minutes. Otherwise, for this kind of problem, I can only think of loading a system recovery point and thus resetting the update that caused it.
How do I do that?
If booting fails several times, you get into a diagnostic environment that can do that. Just press (a few) times Reset, just before the blurry logon screen should appear and at the new start Windows notices that something went wrong and loads the part instead.
By Windows installation medium (DVD or USB stick) you should also be able to achieve the system recovery.
If this does not work for some reason, please create a new question and describe the problem right, most likely someone else will be able to help you better than me.
