what is it? and my firewall always block windows operating system for sum reason
If it’s in your C:\Windows\System32 folder, then it’s a valid Windows process. It is the session manager.
If it is located anywhere else, it is malware.
Are you referring incoming traffic being blocked by the firewall? That is normal. The traffic is not allowed in and since it has no target it would be sent to System it is weren’t blocked.