Closing a window and ending an application are not always the same thing.
A Windows application can continue running without a visible window. Microsoft's Windows App SDK documentation explicitly describes a desktop application as running even when it may have no visible window. [R1]
That does not automatically mean the application is broken.
The first question is:
Is the app intentionally doing useful background work, or did it fail to shut down as expected?
Confirm that the app is really still running
Open Task Manager with Ctrl + Shift + Esc and look under Processes.
If the application or one of its related processes is still present after its window has closed, Windows still has a running process for it.
Do not judge the situation from the taskbar alone. A program may have no open window while its process continues in the background. [R1]
Next, check whether the process is actually using meaningful CPU, memory, disk, or network resources.
A process that remains present but is almost idle is a different problem from one that continues consuming substantial resources.
Some background activity is intentional
Microsoft documents that some apps can continue running when you are not actively using them. They may synchronize data, send notifications, or keep information up to date. [R2]
Examples include messaging, mail, synchronization, update, and notification functions.
Stopping that activity may therefore change how the application behaves. Notifications may stop, synchronization may pause, or the application may take longer to become ready the next time you open it.
The useful question is not:
“Why is there still a process?”
It is:
“What is this process doing, and do I need it to keep doing that?”
Can Windows stop the app from running in the background?
For supported Windows apps, background activity can be controlled through Windows settings.
Microsoft provides Always, Power optimized, and Never background options for apps that support this control. Setting an app to Never stops its background notifications and updates when you are not actively using it. [R3]
Desktop applications are different. Microsoft notes that desktop apps may not be controlled by Windows' background-app permission and may instead need to be configured in the application's own settings. [R2]
If the application provides an option such as continuing to run in the background, staying active after the window closes, or starting a helper process, change that setting there rather than deleting files or registry entries.
What if the app should have closed but did not?
Sometimes an application is not intentionally running in the background. It may be stuck while shutting down or may have become unresponsive.
If the process remains active and the application no longer responds, Task Manager > End task can terminate it. Microsoft documents Task Manager's End task function as a way to close an application that cannot be closed normally. [R4]
Use that as a recovery action, not as the normal way to close an application.
Ending a process can discard unsaved work or interrupt an operation that was still in progress.
What if it keeps coming back?
If the process ends successfully but returns after the next sign-in or restart, the problem is no longer simply “the app did not close.”
Investigate whether the application is configured to start automatically with Windows or whether one of its own background components is designed to launch independently.
Do not repeatedly end the process without identifying what starts it again.
What should I do now?
- Close the application's window normally.
- Open Task Manager and confirm whether the application or one of its related processes is still running.
- Check whether the remaining process is idle or is materially using CPU, memory, disk, or network resources.
- Determine whether the application needs background activity for notifications, synchronization, updates, or another feature you use.
- For supported Windows apps, review the app's background-activity setting.
- For desktop applications, check the application's own settings for background or close behavior.
- If the process is unresponsive and should have exited, use End task only after considering unsaved work.
- If the process repeatedly returns after being ended, investigate its startup or background-launch mechanism instead of repeatedly terminating it.
- If the process remains active but consumes negligible resources and provides functionality you want, no repair may be necessary.
The goal is to distinguish intentional background operation, unnecessary persistence, and a failed shutdown before changing how the application starts or runs.