moriluk you are installing EB in wrong folder.
Make sure you are installing it in folder that has Rome TW.exe file.

So if you have installed RTW in for example:

"C:\Rome Total War" then you can find Rome TW.exe in this directory "C:\Rome Total War\\Rome TW.exe" so when you install EB install it i n"C:\Rome Total War\"

Dont install it in "C:\EB" or "C"\Rome Total War\EB" it has to be "C:\Rome Total War"