Evil sound card, then.
Hmm. If you want to verifiy it's the sound card causing the problem, you can turn it off.
My Computer-control panel-system-hardware-device manager-sound, video, and game controllers-find the sound card-properties-switch the use this device field to disable. Might want to turn off everything under sound to be sure.
That's for XP, it's slightly different for other OS's. Anyway, once you've done this reboot, then try running SF. If it runs you've found the problem and should pester Dell about new drivers. Good luck, you'll need it.
To undo that, just do the same and change to enable.