Actually, MG, replacing a sound card is not all that difficult in a desktop type computer, and the external USB type can be used in most situations, including most laptops. Mine just won't work correctly with the "Pro" version of WinXP. And XP itself won't allow a downgrade to the "Home" version. I'd have to reformat the drive, reinstall windows, reload all my software and restore all my data (yes, I do have backups).
A desktop can also be configured with 2 separate sound cards, as many of my ham radio friends have demonstrated, and a "built-in" type can be easliy disabled if necessary.
If you like, I can advise you via direct email or you can get assistance via search at
http://www.PCWorld.com .
Lee Eschen