Quick answer
Identify the intended drag action before troubleshooting: pinning an application, activating a running window, or dropping a file into that application are different tasks. Use a harmless test file and avoid changing several taskbar settings at once.
What matters for this task
The receiving application determines whether it accepts a file type, while the shell controls how the taskbar responds during the drag. A rejected drop can therefore come from the destination app rather than the taskbar itself.
Steps to follow
- Create or choose a non-sensitive test file that the destination application can open normally.
- Open the destination app and first drag the file directly into its window to establish a baseline.
- Test the taskbar-assisted route, noting whether the app activates, whether its window appears, and whether the final drop is accepted.
- Repeat with a second application and compare with a simple taskbar setup. Keep pinning tests separate from file-drop tests.
Verify the result
Record the exact stage that fails: taskbar hover, window activation, or application acceptance. That tells you where to focus the next check.
Limits and rollback
Revert the last taskbar change if activation stopped working. Do not use administrator elevation as a universal fix for every rejected drop.
Questions about this task
Is pinning an app the same as dropping a file into it?
No. Test those actions separately because they have different destinations and expected outcomes.
What if the app rejects the file even without the taskbar?
Investigate the application and file type before changing StartAllBack settings.
Primary sources
Publisher claims and Windows procedures are linked below. The comparison and diagnostic steps are editorial guidance, not a claim of hands-on Windows testing.
Windows 11 download · Review compatibility and the publisher’s license terms before installing.
Download for Windows 11 File source and installation notes