Hey @BasselKanjo
This usually happens when the Tiberium Wars executable is modified in some way and the Kane's Wrath installation won't detect the executable due to wrong checkrum. Is one of the games on DVD and other loaded from Origin ? Or have you modified the Kane's Wrath executable in some way? In general it would be for the best if both of your games are either digital or both games are physical, otherwise it may have difficulty finding the installations as the Origin versions are modified in order for them to work without the original disc.
I would contact the EA's support with the game codes in hand and asking if they could grant you an Origin version of the game as then they should be surely compatible : https://help.ea.com/en/contact-us/
Is your Tiberium Wars a DVD version as well and it still isn't working ? In that case, make a fresh install with the Tiberium Wars without modifying the executable in the default location, then try and install the Kane's Wrath.
Good luck !
EDIT: Typofix.
In a different thread, he admitted pirating Tiberium Wars, implying that he used an odd variant that Kane's Wrath can't detect. http://answers.ea.com/t5/C-C-The-Ultimate-Collection/How-to-patch-command-and-conquer-3-kanes-wrath-without-dvd/td-p/6206679/jump-to/first-unread-message
I know @plokite95 . I was the one answering to him there. I'm still working by the book as sometimes these threads may help others with similar issues. And hey, he does say he bought Kane's Wrath now.
