How Can You Get Port Royale 2 To Work On Vista Why Do I Get Interference From My Front Ports?

Why do I get interference from my front ports? - how can you get port royale 2 to work on vista

For example, if I plug my headphones or speakers to the back ports of my PC, that sounds good and there is no interference. But when you plug into the front ports I have a kind of digital interference is a kind of enthusiasm, but it is random and boring, and not just a sound.

Why is this happening? And how / How can I solve this problem? Please provide any information that can, cos I have listened to this a long time and even had the same problem with my old PC. Oh, and BTW, no, not the fault of the speakers or headphones, because I tried several speakers and headphones, and all have the same problem.