"corrupt file" error during install

I just bought the game Galactic Civ. 2 : Dread Lords, it does not install.
The forums are quite large and search does not turn up anything and I am
tired of browsing for an answer.

I get the error : "An I/O error occurred while installing a file. This is
normally caused by bad installation media or a corrupt installation
file." ...at 56% of install every time.

I have installed from Disc, as well as from the hard drive (in a separate
folder and in the Stardock folder as well). ALL my PC hardware is less than
1 year old. ALL drivers are up to date. Stores have a no return policy on
software, I could use a hand here. No err log either.

Thanks much much in advance