Reset 10 cmd on Win?

I have (still) a Win 10 laptop, and I would like to do some things with the Win + R CMD system there - but for whatever reason - the name of the actual user, my grandfather (who unfortunately died some time ago)) Can someone help me get this away? Or what or what is it for?

LG Max

(reasonable answers please)

This is the name of the user profile with which you are logged on to the system. If you want to change the name you have to create a new profile.
https://www.heise.de/...58638.html

CD \

That seems to be your username.

Yes, thank you.

That is just the user directory from the CMD starts. You can use cd. Or

Change cd \ to a directory above.

OK thanks.