It sounds like it could be a bad disc. Even if it's been sitting in the box for a period of time, some discs can still go bad. There is also a very, very small percentage of discs that are manufactured with errors.
Unfortunately, Sacrifice is long out of print and we no longer have any replacement discs.
You might try the following:
* Clean the disc, look for scratches.
* Return the game to the place of purchase for a replacement or refund (depending on their policies).
* Try to install the game on another computer. There is a really, really small chance there is some kind of incompatibility between the disc and your DVD-RW drive.