Csrss.exe is the main executable for the Microsoft Client/Server Runtime Server Subsystem. This process manages most graphical commands in Windows. This program is important for the stable and secure running of your computer and should not be terminated.

Csrss.exe is also registered as a Trojan so it is important to note where it is located.

Yours, shown as \\??\C:\Windows\System32, is in the right place as is your Winlogon.

The reason for the two '??' is because specialized code that runs in ring 0, or "kernel mode" that is collectively referred to as "Executive Services" and these two are Executive Services.