Why does the ball on the server not work in the morning until the reboot?

Question

Windows

There is a computer on windows 7, which takes files and folders from a file server (Windows 2008 or 8).
In the morning, a person comes, tries to enter, but it does not work for him, because he does not have rights. Restarts the computer and everything is back to normal.
Where can I look to prevent this from happening?
Computers in the domain, the domain seems to be alive.

Answer 1

Does the network card go to sleep?