Task Manager is the most useful diagnostic tool built into Windows 11. It shows you exactly what is running on your PC, how much CPU, memory, disk, and network each process is using, and lets you force-close anything that has frozen. This guide covers every tab and how to use them to diagnose and fix performance problems.
How to Open Task Manager
- Ctrl + Shift + Esc — opens Task Manager directly, the fastest method
- Ctrl + Alt + Del → Task Manager
- Right-click the taskbar → Task Manager
- Win + X → Task Manager
- Search for Task Manager in the Start menu
Processes Tab — See What Is Running
The Processes tab lists every running application and background process with its current resource usage. The columns show:
- CPU % — percentage of processor being used. Normal idle is 1–10%. Sustained 90–100% indicates a problem.
- Memory — RAM being used by this process
- Disk — read/write activity on the storage drive
- Network — network data being sent or received
- GPU — graphics card usage (useful for identifying GPU-heavy apps)
Click any column header to sort by that resource. This instantly shows you what is consuming the most CPU or memory.
Processes are grouped into three sections: Apps (windows you have open), Background processes (running but not visible), and Windows processes (core operating system components).
How to End a Task
If an app has frozen and is not responding, right-click it in the Processes tab and select End task. Any unsaved work in that app will be lost. Use this as a last resort when a program will not close normally.
Performance Tab — Live Resource Graphs
The Performance tab shows live graphs of CPU, memory, disk, network, and GPU usage over time. Click each resource in the left panel to see its graph and key stats.
CPU
- Utilisation: Current and historical usage percentage
- Speed: Current clock speed (lower than base speed at idle, higher under load due to Turbo Boost)
- Processes / Threads / Handles: Total counts across the system
- Up time: How long since the last restart
Memory
- In use: RAM currently used by processes
- Available: Free RAM ready to be used
- Committed: Total memory reserved (includes virtual memory/paging file)
- Cached: RAM holding recently used data for faster access — this is normal and does not indicate a problem
If Available memory is consistently below 500 MB, your PC needs more RAM or has a memory leak in a running application.
Disk
Shows read/write speeds and active time percentage. Sustained 100% disk usage causes severe slowdowns — common after Windows updates when Search indexing and Defender scanning run simultaneously.
GPU
Shows GPU utilisation, dedicated memory used, and temperature (on supported hardware). High GPU usage during video calls may indicate hardware acceleration is working correctly. Unexpectedly high GPU usage when idle may indicate a background process using the GPU.
App History Tab
Shows cumulative CPU time and network usage per application since the last reset. Useful for identifying apps that consume resources over time rather than in one spike.
Startup Apps Tab
Lists everything that launches at login, with its startup impact rating (High, Medium, Low). Right-click any entry to disable it. See the startup programs guide for full details on what to disable.
Users Tab
On PCs with multiple user accounts, shows resource usage per logged-in user. Useful for seeing if another user’s session is consuming CPU or memory.
Details Tab
A more technical view of every running process with additional columns including PID (Process ID), CPU time, and memory working set. Right-click a process for advanced options including setting CPU priority and CPU affinity (which processor cores the app can use).
To kill a process and all its child processes: right-click → End process tree. This is more thorough than End task.
Services Tab
Lists all Windows services — background components that run independently of user sessions. You can start, stop, and restart services here. Right-click a service → Open Services to open the full Services management console.
Diagnosing Common Problems with Task Manager
PC Is Slow — High CPU
Sort the Processes tab by CPU. Common high-CPU culprits:
- Antivirus (MsMpEng.exe / Windows Security) — scanning. Wait for it to finish.
- Windows Update (TiWorker.exe, svchost.exe) — installing updates. Wait.
- SearchIndexer.exe — rebuilding search index after an update. Wait.
- Browser with many tabs open — close unused tabs or use a browser with tab sleeping
PC Is Slow — High Disk
Sort by Disk. If the system drive is at 100%, the same post-update processes are usually responsible. Check the Performance tab → Disk for read/write speed — if it is maxed at the drive’s rated speed, it is a busy drive, not a broken one.
App Is Frozen
The Status column shows Not responding for frozen apps. Wait 30 seconds — some apps recover. If not, end the task.
