Turns out that Creative - the company that mfg. the soundcard - doesn't have drivers for the Sound Blaster Live! under Vista or Windows 7. Probably want you to spend money on a new soundcard instead :P
But a bit of Googling revealed the somewhat tedious workaround.
- Goto Creative's support website and download the WinXP driver for the Sound Blaster Live! The filename is LiveDrvUni-Pack(ENG).exe
- Before you run the file, right-click on it and choose "Troubleshoot compatibility." Then select "Troubleshoot program."
- Select "Program worked in earlier versions of Windows..." and click "Next."
- Select "Windows XP (SP2)" and click "Next."
- Select "Start the program" and click "Next."
- Select "Yes to save" and click "close."
Now the driver install program will successfully run, and when you restart - you should have sound. Yes, all that work because Creative got greedy and decided they'd try to force you to buy a new soundcard ;)
Update: There is also an independent project to write a WDM-type driver which supports the Live! and any, other EMU10K1 and EMU10K2-based soundcard - the kX Project. Word has it that this requires some tweaking once installed, but they do list Windows 7 as a supported OS.