Hi
OK I can see where you are now............It's not a Windows setting.
If VideoPad is open and you then plug in your camera you originally got this window.......

.......and it is THIS window you clicked the "Don't ask me again " box.
You can reinstate this prompt by clicking... Tools/Options/Media/....
Then click (tick) the box marked "Ask to add files to the project when removable media is connected to the PC" Followed by OK.
That should solve your problem.
Nat