|Original author(s)||David Plummer|
|Initial release||August 24, 1996|
|Operating system||Windows NT 4.0 and onwards|
|Platform||IA-32, x86-64, ARM and Itanium (and historically DEC Alpha, MIPS, and PowerPC)|
|Type||Task manager, system monitor and startup manager|
Task Manager, previously known as Windows Task Manager, is a task manager, system monitor, and startup manager included with Microsoft Windows systems. It provides information about computer performance and running software, including name of running processes, CPU load, commit charge, I/O details, logged-in users, and Windows services. Task Manager can also be used to set process priorities, processor affinity, start and stop services, and forcibly terminate processes.
The program can be started in recent versions of Windows by pressing + and then typing in
taskmgr.exe, by pressing ++ and clicking Start Task Manager, by pressing ++, by right-clicking on the Windows taskbar and selecting "Task Manager", or by typing "taskmgr" in the File Explorer address bar.
Task Manager was introduced in its current form with Windows NT 4.0. Prior versions Windows NT, as well as Windows 3.x, includes the Task List application, is capable of listing currently running processes and killing them, or creating a new process. Windows 9x has a program known as Close Program which lists the programs currently running and offers options to close programs as well shut down the computer.
Task Manager has two views. The first time Task Manager is invoked by a user, it shows in a simplified summary mode (described in the user experience as Fewer Details). It can be switched to a more detailed mode by clicking More Details. This setting is remembered for that user on that machine.
In summary mode, Task Manager shows a list of currently running programs that have a main window. It has a "more details" hyperlink that activates a full-fledged Task Manager with several tabs.
Right-clicking any of the applications in the list allows switching to that application or ending the application's task. Issuing an end task causes a request for graceful exit to be sent to the application.
The Processes tab shows a list of all running processes on the system. This list includes Windows Services and processes from other accounts. The Delete key can also be used to terminate processes on the Processes tab. By default the processes tab shows the user account the process is running under, the amount of CPU, and the amount of memory the process is currently consuming. There are more columns that can be shown. The Processes tab divides the process into three categories:
This tab shows the name of every main window and every service associated with each process. Both a graceful exit command and a termination command can be sent from this tab, depending on whether the command is sent to the process or its window.
The Details tab is a more basic version of the Processes tab, and acts similar to the Processes tab in Windows 7 and earlier. It has a more rudimentary user experience and can perform some additional actions. Right-clicking a process in the list allows changing the priority the process has, setting processor affinity (setting which CPU(s) the process can execute on), and allows the process to be ended. Choosing to End Process causes Windows to immediately kill the process. Choosing to "End Process Tree" causes Windows to immediately kill the process, as well as all processes directly or indirectly started by that process. Unlike choosing End Task from the Applications tab, when choosing to End Process the program is not given warning nor a chance to clean up before ending. However, when a process that is running under a security context different from the one of the process which issued the call to TerminateProcess, the use of the KILL command line utility is required.
The Performance tab shows overall statistics about the system's performance, most notably the overall amount of CPU usage and how much memory is being used. A chart of recent usage for both of these values is shown. Details about specific areas of memory are also shown.
There is an option to break the CPU usage graph into two sections: kernel mode time and user mode time. Many device drivers, and core parts of the operating system run in kernel mode, whereas user applications run in user mode. This option can be turned on by choosing Show kernel times from the View menu. When this option is turned on the CPU usage graph will show a green and a red area. The red area is the amount of time spent in kernel mode, and the green area shows the amount of time spent in user mode.
The Performance tab also shows statistics relating to each of the network adapters present in the computer. By default the adapter name, percentage of network utilization, link speed and state of the network adapter are shown, along with a chart of recent activity.
The App History tab shows resource usage information about Universal Windows Platform apps. Windows controls the life cycle of these apps more tightly. This tab is where the data that Windows has collected about them can be viewed.
The Startup tab manages software that start with Windows shell.
The Users tab shows all users that currently have a session on the computer. On server computers, there may be several users connected to the computer using Terminal Services. As of Windows XP, there may also be multiple users logged onto the computer at one time using the Fast User Switching feature. Users can be disconnected or logged off from this tab.
Task Manager was originally an external side project developed at home by Microsoft developer David Plummer; encouraged by Dave Cutler and coworkers to make it part of the main product "build" he did so in 1995, donating the project. The original task manager design featured a different Processes page with information being taken from the public Registry APIs rather than the private internal operating system metrics.
A Close Program dialog box comes up when ++ is pressed in Windows 9x. Also, in Windows 9x, there is a program called Tasks (TASKMAN.EXE) located in the Windows directory. TASKMAN.EXE is rudimentary and has fewer features. The System Monitor utility in Windows 9x contains process and network monitoring functionality similar to that of the Windows Task Manager. (Also, Tasks program is called by clicking twice on desktop if Explorer process is down.)
In Windows XP only, a Shutdown menu is present that provides access to Standby, Hibernate, Turn off, Restart, Log Off, and Switch User. Later versions of Windows make these options available through the start menu.
On the Performance tab, the display of the CPU values was changed from a display mimicking a LED seven-segment display, to a standard numeric value. This was done to accommodate non-Arabic numeral systems, such as Eastern Arabic numerals, which cannot be represented using a seven-segment display.
The users tab is introduced by Windows XP.
Beginning with Windows XP, the Delete key is enabled on the Processes tab.
In Windows 8, Windows Task Manager has been overhauled and the following changes were made:
Task Manager is a common target of computer viruses and other forms of malware; typically malware will close the Task Manager as soon as it is started, so as to hide itself from users. Variants of the Zotob and Spybot worms have used this technique, for example. Using Group Policy, it is possible to disable the Task Manager. Many types of malware also enable this policy setting in the registry. Rootkits can prevent themselves from getting listed in the Task Manager, thereby preventing their detection and termination using it.