Patch Trouble

I am having probs getting the patch to install correctly. I am using Win XP on an Alienware Grey machine. When I goto install the patch it gives me a "corrupt installation file" message. I have downloaded the patch twice and still the same message. After I apply the patch the program is unusable and I have to uninstall then install again. I feel like I'm being left out with the lack of the update. Can someone me with this? This is definitely the best space strategy game made and I want to play it with full ability. Thanks in advance.