|sounds like you MAY have stumbled across the solution already: Verify whether the disk you have is a CD or a DVD - it should say right on the disk itself. And if your drive says CD on the front but not DVD, it is not a DVD reader. They look similar, but they're totally different.|
If you determine that your installation media Sims disk is a DVD and you only have a CD drive, your only option is to acquire a DVD drive. You can usually find decent ones for about $30 though, and they are worth having.