Remote desktop in window 10 cannot access computer having windows 8

What exactly happens, or doesn't happen? What error message, if you get one, do you get? We need more info / details.

maideen5 said:

thank you for all of your feed back. Previously I could connect the Window 8 through my pc (Window 10). Once auto updated Windows 10 couple of week ago, I experienced this situation.

We need to know a lot more before we can help you.

What was the update a few weeks ago? Was it a cumulative update, or the April 2018 Update to version 1803?
Look at 'View update history' in Settings > Update & Security'.

If you open File Explorer can the W10 PC see the name of the W8 PC in Network?

When you try to use Remote Desktop to connect to the W8 PC, what errors do you see?
Post screenshots of the errors if you can.
How to Upload and Post Screenshots and Files at Ten Forums | Windows 10 Tutorials

You have mentioned Server 2012. Are these PCs members of a Domain?