Laptop is very slow. After restart, it shows “The User Profile Service service failed the sign-in. User profile can not be loaded”. How do I fix this?

System settings:

Prozessor Intel(R) Core(TM) i5-4210M CPU @ 2.60GHz   2.59 GHz
Installierter RAM 8,00 GB
Speicher  238 GB SSD Samsung SSD 850 PRO 256GB, 238 GB SSD Crucial_CT256MX100SSD1
Grafikkarte   Intel(R) HD Graphics 4600 (113 MB)
Produkt-ID    00325-80000-00000-AAOEM
Systemtyp 64-Bit-Betriebssystem, x64-basierter Prozessor

On this older Lenovo ideapad with 8 GB RAM and Windows 10, I ran into very slow laggy system speed independent from the program, that is, even if I opened the task manager or just clicked somewhere. I had just installed and run Evernote which took 500 MB RAM up to 6 GB of the 7.3 GB as the task manager showed, which might have caused this, but I am not sure about it.

I restarted and found an error popping up in front of a bluescreen that I had to accept with “OK”, and only afterwards, the Windows login code came up:

“The User Profile Service service failed the sign-in.

User profile can not be loaded”

enter image description here

Or on a German Windows, it was:

“Fehler bei der Anmeldung des Diensts “Benutzerprofildienst”.

Das Benutzerprofil kann nicht geladen werden.”

When I entered Windows after a longer time than normal, I found that all of my data on the desktop screen and my links in the taskbar were gone.

I found a few guides that dealt with this error after new accounts or upgrades. Yet, I did not change anything of that kind and fear to touch Windows system files. Here is a list of those questions which do not match even though they deal with the same error:

Without having had a new account or upgrade or system change, what can I do to get the user profile data back at best?