Services running - are they needed ?

StartUp Sstem Files

smss.exe - This is the session manager subsystem, which is responsible for starting the user session. This process is initiated by the system thread and is responsible for various activities, including launching the Winlogon and Win32 (Csrss.exe) processes and setting system variables.

Local Security Authentication Server - lsass.exe

What does it do?
lsass.exe - It generates the process responsible for authenticating users for the Winlogon service. This process is performed by using authentication packages such as the default Msgina.dll. If authentication is successful, Lsass generates the user's access token, which is used to launch the initial shell. Other processes that the user initiates inherit this token.