Use Microsoft Sysinternals Autoruns to identify and disable the scheduled task, service, or Explorer extension launching the transient command window, because ordinary Startup apps cover only some automatic-start locations.
1. Inspect the broader auto-start locations
Autoruns shows scheduled tasks, services, Explorer extensions, logon entries, and other locations that Task Manager’s Startup apps does not cover.^1^
- Download and extract Autoruns, then right-click Autoruns64.exe and select Run as administrator.
- In Options, enable:
- Hide Microsoft Entries
- Verify Code Signatures
- Check these tabs first:
- Scheduled Tasks
- Services
- Explorer
- Logon
- Look for third-party entries that:
- Run
cmd.exe,powershell.exe, a.bat,.cmd, or script file. - Have no publisher or show Not Verified.
- Point to a missing file.
- Belong to recently installed browser utilities, update tools, device utilities, or extensions.
- Run
- Right-click a suspicious entry and use Properties or Jump to Entry to inspect its publisher, executable path, and command.
- Clear its checkbox to disable it temporarily; do not delete it yet.
- Restart Windows and test Chrome, Edge, and File Explorer.
If the flashing stops, re-enable the entry once to confirm it is responsible. Then update or uninstall the associated application, or leave that entry disabled. Autoruns supports disabling an entry by clearing its checkbox; deletion is a separate action.^1^
2. Capture the process if Autoruns does not reveal it
Process Monitor records process activity, including the image path, command line, user, session, and parent-child process relationships.^2^
- Download and extract Process Monitor.
- Run the correct version as administrator—normally Procmon64.exe on a 64-bit PC.
- Press Ctrl+X to clear existing events.
- Ensure capture is active with Ctrl+E.
- Use the PC until the window flashes, then immediately press Ctrl+E again to stop capture.
- Open Tools → Process Tree and inspect processes launched at that time.
- Look for
cmd.exe,conhost.exe,powershell.exe, or a script host. Open the event properties and record:- Parent process
- Image path
- Command line
- Publisher/signature
The parent process usually identifies the program or task that needs to be updated, uninstalled, or disabled. Process Monitor capture starts automatically and can be stopped with Ctrl+E.^3^
3. If it appears to be a third-party service
Since some Startup apps have already been disabled without resolving it, test the remaining non-Microsoft services rather than repeating the same Startup-app test:
- Search for msconfig and open System Configuration.
- Select Services.
- Select Hide all Microsoft services first.
- Record the currently enabled services, then select Disable all.
- Restart and test.
If the flashing stops, re-enable half of the services, restart, and test again. Repeat by halves until one service is isolated. Re-enable the other services afterward. A clean boot can temporarily remove functionality, so do not disable Microsoft services.^4^
4. Run an offline security scan if the launcher is unknown
An unexpected unsigned executable, a file in an unusual location, or repeated launching with no recognizable owner warrants an offline scan:
- Save all open work.
- Open Windows Security → Virus & threat protection → Scan options.
- Select Microsoft Defender Antivirus (offline scan).
- Select Scan now.
The computer restarts and scans outside normal Windows, making persistent malware more difficult to hide. After Windows restarts, check Windows Security → Protection history for results.^5^
Do not delete unknown Autoruns entries or files until their executable path and publisher have been identified; disabling the entry first is reversible.
References