I found Marek-pc on my PC

In Network places I found one besides "mine" that is called Workgroup and contains Marek-pc.
If I click it brings up a sign in window.
I found the same thing on my wife's computer. Her email address would come up in the dropdown window, but the only password she has ever used does not work, so almost certainly was not created by me.
Very suspicious stuff.
How do I get rid of these?
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Fred MarshallPrincipalCommented:
It looks like there is or was a computer connected to your network named Marek-PC with the workgroup name of Workgroup.

Sometimes these names persist after the computer is gone.  So might it have been your visiting friend's laptop or ...... ?

Or, might it have been someone who connected to your wireless?

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Windows Networking

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