Since you have already gone through the format process, and presumably have re-activated Windows, be sure to set Restore Points after each successful installation of any hardware or software. You should allow the maximum System Restore disk space setting, until things have settled down, after which you can reduce it to half the amount of space.
Did you search Creative.com to see if they have a cleanup utility for uninstalling Media Source applications? If not, reinstall the old card, then boot up and reinstall the drivers, applications and Media Source application completely, using the same installation files as were used originally, then reboot, then uninstall all of it and shut down. Remove the sound card and reboot. Open the Windows Registry (Start > Run > Regedit) and search for anything named "Creative" that was left behind and delete those branches and keys. Then, look in Program Files for any Creative folders that were left behind and delete those.
It can be a headache to cleanup after a partial uninstall of a badly behaved program or drivers. Sometimes a Registry Cleanup tool comes in handy at these times. jv16 PowerTools, from Macecraft.com, is among the best, with their
RegSupreme Pro having good reviews by Fred Langa and others. These are paid programs, but they do have 30 day trial periods, with pretty much full functionality.
Here is what they say about RegSupreme Pro, which you may find useful:
Remove hidden traces of software you thought you uninstalled ages ago.