I think every time I turn on the computer, the alert set by my excel form will automatically pop up on the desktop when it's time! Can it be realized?

This is possible, but not recommended.

1, because the Excel table file itself is not an execution file, so you need to open the Excel program.

2. It needs to be implemented by VBA.

way

1. This file needs to be started automatically in the windows scheduled task.

2. In Excel VBA, judge whether the time has reached the specified time or how many seconds in advance, automatically maximize this Excel file and pop up the Msgbox message box.