People! Thank you for helping me out, I finally found the game I was searching for.
It was not "Earth 2140" or "Earth 2150" which looks kind of cool. It was not "Total Annihilation" or "Moon Project".
The game was released in 1998, so I was one year of. I suddenly remembered that the name had either "Alien" or "Breed" in it's name. I started searching for a game which contain "Alien" in it's name around '95 to 97, but I didn't find the one I was searching for. Then I tried "breed" and yes! Finally I found it!
It is a game called "Warbreeds" from 1998, created by Red Orb Entertainment.
Here is a quick review by Gamespot:
http://uk.gamespot.com/pc/strategy/warbreeds/review.html?om_act=convert&om_clk=gssummary&tag=summary;read-review
I just want to thank everybody for their help! It is a great way to feel welcomed to the forum