Oliver welcome to the forums.
Have you done a thorough cleaning after all those driver installs? If not I would start with uninstalling anything Creative related in Programs and Features as well as uninstall the card (if still showing) in Device Manager. Then reboot and go into safe mode and use this, Guru3D - Driver Sweeper
to get rid of anything left. Then try just the X-Fi Support Pack 2.0. It may also take moving the card to another slot (if available) to get it to work properly (had to do just that with an Audigy 4 that had worked flawlessly in XP but started acting up when I installed Vista).
For nabilalk, what model is your SB Live (actual number on the card that will be either CTxxx or SBxxx)?