Default processes in Task Manager

Default processes in Task Manager

CISVC.EXE – Indexing Service for local file searching.

CSRSS.EXE - Client Server Runtime Process, for running console windows, creating and/or deleting threads, and part of the 16-bit virtual MS-DOS environment.

CTFMON.EXE - Cicero Loader, Office XP speech recognition program.

EXPLORER.EXE – Windows Explorer, user shell, taskbar, desktop etc.

LSASS.EXE – LSA(local security authentication) Executable and Server DLL, responsible for
authenticating users for the Winlogon service

MDM.EXE - Machine Debug Manager, provide application debugging for MS IE, FrontPage, Office etc.

MSTASK.EXE - Task Scheduler Service, running program/service at specific period.

REGSVC.EXE – Remote Registry Service, accessing/managing registry remotely.

SERVICES.EXE - Services Control Manager, for starting, stopping, and interacting with system services.

SMSS.EXE - Session Manager Subsystem, for starting user session (i.e. launching the Winlogon and Win32 (Csrss.exe) processes and setting system variables).

SPOOLSV.EXE – Spooler Service, for managing prints and fax jobs.

STISVC.EXE - Still Image Service for digital cameras and scanners.

SVCHOST.EXE - Generic Process, acts as a host for other processes running from dlls (dynamic link library).

SYSTEM – System processing time.

SYSTEM IDLE PROCESS - Processor time when the system isn't processing other threads.

TASKMGR.EXE - Windows Task Manager itself.

WINLOGON.EXE – Process for managing user logon and logoff.

WINMGMT.EXE - Windows Management Instrumentation, for application client management.

For more info, check this.
http://support.microsoft.com/default.aspx?scid=kb;en-us;263201&Product=win2000

http://www.liutilities.com/products/wintaskspro/processlibrary/