Each process running in Microsoft Windows is assigned a unique decimal number called the process ID, or PID. This number is used to specify the process when attaching a debugger to it.
There are several ways to determine the PID for a given application: using the Task Manager, using the tasklist command, using the TList utility, or using the debugger.
The Task Manager may be activated in a number of ways, but the simplest is to press CTRL+ALT+DELETE and then click Task Manager.
If you select the Processes tab, each process and its PID will be listed, along with other useful information.
Some kernel errors may cause delays in Task Manager's graphical interface.
The Tasklist Command
In Windows XP and later versions of Windows, you can use the tasklist command from a Command Prompt window. This displays all processes, their PIDs, and a variety of other details.
TList (Task List Viewer, tlist.exe) is a command-line utility that displays a list of tasks, or user-mode processes, currently running on the local computer. TList is included in the Debugging Tools for Windows package.
When you run TList from the command prompt, it will display a list of all the user-mode processes in memory with a unique process identification (PID) number. For each process, it shows the PID, process name, and, if the process has a window, the title of that window.
For more information, see TList.
The .tlist Debugger Command
If there is already a user-mode debugger running on the system in question, the .tlist (List Process IDs) command will display a list of all PIDs on that system.
CSRSS and User-Mode Drivers
To debug a user-mode driver running on another computer, debug the Client Server Run-Time Subsystem (CSRSS) process. For more information, see Debugging CSRSS.