Audio Help no sound XP - no audio device but all drivers installed

I have been on a couple of forums but none as yet have been able to help fix my no sound problem?? : ( I had a Trojan a good few month's ago and after installing avg, getting rid of the virus and then uninstalling avg i lost all sound. Installed sound driver and codecs again but still nothing - now i have a yellow exclamation mark over the multimedia audio driver.
Please please some one help -

Please see system info below.

OS Name Microsoft Windows XP Professional
Version 5.1.2600 Service Pack 3 Build 2600
OS Manufacturer Microsoft Corporation
System Name THAMILIN-
System Manufacturer Packard Bell NEC
System Model 00000000000000000000000
System Type X86-based PC
Processor x86 Family 15 Model 2 Stepping 7 GenuineIntel ~2489 Mhz
BIOS Version/Date American Megatrends Inc. 3.0B, 11/2/2002
SMBIOS Version 2.3
Windows Directory C:\WINDOWS
System Directory C:\WINDOWS\system32
Boot Device \Device\HarddiskVolume2
Locale United States
Hardware Abstraction Layer Version = "5.1.2600.5512 (xpsp.080413-2111)"
User Name THAMILIN-\kabellan
Time Zone GMT Standard Time
Total Physical Memory 256.00 MB
Available Physical Memory 16.38 MB
Total Virtual Memory 2.00 GB
Available Virtual Memory 1.96 GB
Page File Space 4.18 GB
Page File C:\pagefile.sys


Name C-Media AC97 Audio Device
Manufacturer C-Media
Status Error
PNP Device ID PCI\VEN_1039&DEV_7012&SUBSYS_20071631&REV_A0\3&61AAA01&0&17
I/O Port 0x0000C800-0x0000C8FF
I/O Port 0x0000C400-0x0000C47F
IRQ Channel IRQ 11