It says locate the .exe file on the computer but i dont have one.please tell me what to do

It request the exe file for the game not for anything else.
If you have not that exe file so you need to redownload the game.
Then if there was no exe file then the game is not original or not a good copy.
Done!

I want to play aoe2 online what can i do? also,plz tell me how do i install the exe file?
the game is a repack by mrr dj

Hi there,

Please understand that Voobly is just a match making platform for you to be able to play the game online with other players. So you have to have a working copy of the game pre-installed on your system before you step into Voobly.

AOE2 is a licensed game that you will need to purchase. We do not encourage piracy and I would recommend that you get your game copy from an online/offline store. If you are unable to grab a copy of the game, you could also opt to purchase a downloadable copy of the game in HD from Steam.

Please follow the steps mentioned here to perform a clean installation of the game:
http://support.voobly.com/display/vkb/KB1019+Clean+installation+of+Age+of+Empires+II+with+the+latest+patches

In case of HD version, please follow the steps mentioned here to perform a clean installation of the game:
http://support.voobly.com/display/vkb/KB1054+Clean+installation+of+Aoe2HD+with+compatibility+patch