Im having the same problems with the audio controller. What really strikes me is that yesterday I could hear things fine, and today Im unable to hear anything out of my headphones. Here's what I get from Belarc:
Operating System
Windows XP Professional Service Pack 2 (build 2600)
System Model
ECS M848A 5.0
Enclosure Type: Desktop
Processor a
1.60 gigahertz AMD Athlon XP
128 kilobyte primary memory cache
256 kilobyte secondary memory cache
Main Circuit Board b
Board: ECS M848A 5.0
Bus Clock: 133 megahertz
BIOS: American Megatrends Inc. 07.00T 04/02/01
Drives
80.02 Gigabytes Usable Hard Drive Capacity
50.25 Gigabytes Hard Drive Free Space
52X24X52 CD-RW [CD-ROM drive]
JLMS XJ-HD166S [CD-ROM drive]
3.5" format removeable media [Floppy drive]
WDC WD800BB-00DKA0 [Hard drive] (80.03 GB) -- drive 0, s/n
WD-WMAHL3233500, rev 77.07W77, SMART Status: Healthy
Memory Modules c,d
512 Megabytes Installed Memory
Slot '0' has 512 MB
Slot '1' is Empty
Slot '2' is Empty
Slot '3' is Empty
Local Drive Volumes
c: (NTFS on drive 0) 80.02 GB 50.25 GB free
Network Drives
None detected
Users
local user accounts last logon
Mike 3/2/2007 3:14:35 PM (admin)
local system accounts
Administrator never (admin)
ASPNET never
Guest 10/22/2005 11:03:11 AM
HelpAssistant never
SUPPORT_388945a0 never
DISABLED Marks a disabled account; LOCKED OUT Marks a locked account
Controllers
Standard floppy disk controller
Primary IDE Channel [Controller]
Secondary IDE Channel [Controller]
SiS PCI IDE Controller
Display
NVIDIA GeForce FX 5200 [Display adapter]
LGE L1722P [Monitor] (17.1"vis, January 2005)
Bus Adapters
SiS 7001 PCI to USB Open Host Controller (2x)
SiS PCI to USB Enhanced Host Controller
Multimedia
Game Port for Creative
SB PCI(WDM)
Communications
U.S. Robotics V.92 PCI Faxmodem #2
Netopia 802.11b WLAN USB Adapter #5
primary Auto IP Address: 192.168.1.4 / 24
Gateway: 192.168.1.254
Dhcp Server: 192.168.1.254
Physical Address: 00:02:78:E8:A5:9D
SiS 900-Based PCI Fast Ethernet Adapter
Dhcp Server: none responded
Physical Address: 00:19:21:70:B3

C
Networking Dns Server: 192.168.1.254
Other Devices
Standard 101/102-Key or Microsoft Natural PS/2 Keyboard
Microsoft PS/2 Mouse
Generic USB Hub
USB Root Hub (3x)
Hope this can help, I want my sound back

(My sound and audio devices are set to headphones rather than speakers too)