I am 99% certainly off topic with this answer, but if the computer/harddrive has installed packages since earlier from ex External harddrive etc or / with AoE3/Mod material then those hidden files can prove ‘spooky/malicious’ to the game.
Unistall the game, delete remaining aoe3 folders, mini-files etc.
Then install again.
Ignore this post if the computer hasnt ever been in contact with AoE3 material before.
… Otherwise if the CD -disc is older than the invention of windows 10, maybe a mini-patch is needed to be downloaded for your disc to function…
I remember doing something like that twice in the past.
I ended up googling it or something.
Sorry for only raising more questions.