Task Manager (Windows)

Task manager application included with the Windows NT family of operating systems

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 and GPU 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 Task Manager, by pressing , by using Windows Search in the Start Menu and typing taskmgr, by right clicking on the Windows taskbar and selecting "Task Manager", by typing taskmgr in the File Explorer address bar, or by typing taskmgr in Command Prompt or Windows PowerShell. Task Manager was introduced in its current form with Windows NT 4.0. Prior versions of Windows NT, as well as Windows 3. x, include the Task List application, are capable of listing currently running processes and killing them, or creating new processes. 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.

Since Windows 8, 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. Since at least Windows 2000, the CPU usage can be displayed as a tray icon in the task bar for quick glance.

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 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, and then be viewed at a later time.

The Startup tab manages software that starts 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 (or the Fast User Switching service, on Windows XP). 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 donated the project in 1995. 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. Prior to Windows XP, process names longer than 15 characters in length are truncated. This problem is resolved in Windows XP. 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 The color used for these heat maps is blue, with darker color again indicating heavier utilization. Hovering the cursor over any logical processor's data now shows the NUMA node of that processor and its ID. A new Startup tab has been added that lists running startup applications. Previously, MSConfig was in charge of this task, or in Windows Vista only, the "Software Explorer" section of Windows Defender. The Windows Defender that shipped built into Windows 7 lacked this option, and it was also not present in the downloadable Microsoft Security Essentials either. The Processes tab now lists application names, application status, and overall usage data for CPU, memory, hard disk, and network resources for each process. A new App History tab is introduced. The application status can be changed to suspended. The normal process information found in the older Task Manager can be found in the new Details tab.

The Processes tab is divided into categories. Display GPU information in the Performance tab, if available.

Windows 11 22H2 has introduced a redesigned Task Manager.

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. Some malware will also disable task manager as an administrator. 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.