I'm having the same problem. Recently reformatted and now my sound doesnt work. the yellow icon appears for the multimedia audio controller
Operating System System Model
Windows XP Professional Service Pack 2 (build 2600) Gateway H5046 400
System Serial Number: GRA6740000729
Enclosure Type: Desktop
Processor a Main Circuit Board b
3.07 gigahertz Intel Pentium 4
16 kilobyte primary memory cache
1024 kilobyte secondary memory cache Board: Micro Star International MS-7173R A-13
Serial Number: 6510276616
Bus Clock: 133 megahertz
BIOS: Phoenix Technologies, LTD W7173AE7 1.0M 05/26/2006
Drives Memory Modules c,d
200.03 Gigabytes Usable Hard Drive Capacity
193.73 Gigabytes Hard Drive Free Space
TSSTcorp CD/DVDW TS-H552D [CD-ROM drive]
Generic USB CF Reader USB Device [Hard drive] -- drive 2
Generic USB MS Reader USB Device [Hard drive] -- drive 4
Generic USB SD Reader USB Device [Hard drive] -- drive 1
Generic USB SM Reader USB Device [Hard drive] -- drive 3
WDC WD2000BB-22RDA0 [Hard drive] (200.05 GB) -- drive 0, s/n WD-WMANL1450556, rev 20.00K20, SMART Status: Healthy 384 Megabytes Installed Memory
Slot 'A0' has 512 MB
Slot 'A1' is Empty
Local Drive Volumes
c: (FAT32 on drive 0) 4.12 GB 1.03 GB free
d: (NTFS on drive 0) 195.91 GB 192.70 GB free
Network Drives
None detected
Users (mouse over user name for details) Printers
local user accounts last logon
Ben 9/28/2007 11:17:28 PM (admin)
local system accounts
Administrator never (admin)
Guest never
HelpAssistant never
SUPPORT_388945a0 never
DISABLED Marks a disabled account; LOCKED OUT Marks a locked account
None detected
Controllers Display
Standard floppy disk controller
ATI IDE Controller
Primary IDE Channel [Controller] (2x)
Secondary IDE Channel [Controller] (2x)
Standard Dual Channel PCI IDE Controller ATI RADEON XPRESS 200 Series [Display adapter]
ViewSonic VA902b [Monitor] (19.1"vis, s/n PSW060774901, February 2006)
Bus Adapters Multimedia
Standard Enhanced PCI to USB Host Controller
Standard OpenHCD USB Host Controller (2x) Creative SB Live! Value (WDM)
Creative SBLive! Gameport
Communications Other Devices
Realtek RTL8139 Family PCI Fast Ethernet NIC
primary Auto IP Address: 192.168.1.64 / 24
Gateway: 192.168.1.254
Dhcp Server: 192.168.1.254
Physical Address: 00:16:17:5E

0:5B
Networking Dns Server: 192.168.1.254
HID-compliant consumer control device
HID-compliant device (2x)
USB Human Interface Device (2x)
PS/2 Keyboard
Logitech HID-compliant Cordless Mouse
USB Composite Device
USB Mass Storage Device
USB Root Hub (3x)
Thanks