Problems with DirectX

[squirtis]

i just bought a 256MB Video Card and a 1GB memory upgrade for my computer, just for CIV IV. when i tried to install the DIRECTX, as prompted during the install of civ iv, i t told me "DirectX setup: A cabinet file necessary for installation cannot be trusted. Please verify the cryptographic services are enabled and the cabinet file certificate is valid." i contacted microsoft and they gave me instructions on how to check my cryptographic services and they were set to automatic. I am completely lost now on what to do, has anyone else experienced this problem or come up with a way to resolve it? I NEED TO PLAY THIS GAME!! help a brother out.