My windows 10 laptop somehow does not work, I'm not familiar with it either. I haven't used it for a long time, I just opened it and I can't open the apps on the taskbar. Then comes the notification "class not registered" the windows button does not work and when you click on it it does not react either. However, normal apps can be opened. Why is this and how can I fix it? It is also way too slow.
I don't mean to be rude but the description is really inadequate and we don't know what you did with it or what was last, so one can only guess.
How about if you, for example, take screenshots or use your mobile phone to take pictures of what does not work and what errors arise that would be helpful.
Usually just take the media tool and reinstall Windows
Does the keyboard work?
Is Windows activated ("Activate Windows" in gray at the bottom right)?
Have you tried restarting?
Did you open the task manager and check how busy the CPU is? (Ctrl + Shift + ESC)
This could possibly be due to updates loading and installing in the background, which can only be assumed with such a "milky" error description.
Wait to see if a restart is announced or to ask a friend who is more familiar with it.