Well, "Setup-AllMyNotes-Deluxe-Edition.exe" wasn't running, as it didn't show up in Task Manager's main "Processes" tab, nor in the "Details" tab, and the installer had finished the installation and had exited for a while. Later in the day I had to turn my computer off for another reason, and after restarting it I could delete the file. My hunch is that a file handler for some reason wasn't closed before the executable exited (maybe it's handled by another process, a zombie thread, or something?), and that's the reason Windows wouldn't allow it to be deleted.

I run Windows 10 Enterprise version 20H2 (compilation 19042.928), plus Kaspersky Total Security 21.3.10.391(b) and SUPERAntiSpyware 10.0.1222.

"Vladonai Software Software Distribution System" is Setup-AllMyNotes-Deluxe-Edition.exe. Kill it using task manager and you will be able to delete it from disk.

By the way, what Windows version you are using?

I just installed version 3.41. After the installation was finished, I tried deleting the installer, but Windows kept preventing me from doing so, saying that "Setup-AllMyNotes-Deluxe-Edition.exe" is in open and in use by "Vladonai Software Software Distribution System". Looking into Task Manager, however, shows no app with that name, or anything similar, running.

So, what's the executable of this "Vladonai Software Software Distribution System"? I'd like to force-close it so that Windows will then allow me to delete "Setup-AllMyNotes-Deluxe-Edition.exe" without a reboot.