What is csrss.exe

This is the user-mode portion of the Win32 subsystem; Win32.sys is the kernel-mode portion. Csrss stands for Client/Server Run-Time Subsystem, and is an essential subsystem that must be running at all times. Csrss is responsible for console windows, creating and/or deleting threads, and implementing some portions of the 16-bit virtual MS-DOS environment.

Note: The csrss.exe file is located in the folder C:WindowsSystem32. In other cases, csrss.exe is a virus, spyware, trojan or worm!