Hi Nebojsa,
Welcome to the Vista Forums.
I have had a quick look for suitable drivers for you. Unfortunately, there are no suitable drivers available for your Creative card, so you will have to stick with the Realtek solution. Here are a couple of links for you, the first to Gigabyte's download page for your motherboard (note that the version of the audio driver is R1.87). The second is to the Realtek page (note that you have to accept the disclaimer before being able to access the main page, and the version of the driver here is R1.91). I use the Realtek AC'97 codec, and the latest driver is fully WHQL certified, so there is a chance that this one will be as well.
Dwarf
GIGABYTE - Support - Motherboard - Driver - GA-8I945P-G-RH Realtek