have sound but sounds odd...

[Warhammer08]

heres the low down..
things were goin fine until i loaded my comp one day and noticed the sound was acting up.. things didnt sound normal. you could still hear sound, just no bass, no vocals...only high pitched sounds on top of which sound like they are in a cave or something.. major echo and scratchy sounding.Also noticed applications that play music(real player fruity loops ect, glitch/pause/stop making music when you click another windo in the background, but if you minimize it then click another application it still makes sound just crackls between?!?!...noticed some lag also so i got the avria virus scan since since i heard avg and windows defender arent that great..did a scan and found a trojan in an .mp3 i downloaded..when i looked it up i noticed it read that this trojan targets the sound codecs and audio drivers so i put 2 & 2 together and figured this the cause of the sudden problem with my sound. having done little with codecs, i simply uninstalled the driver and rebooted.. weeeell nothing changed..so i invited a friend over who claimed having worked on "this type of thing befor" and after a few hours of nothing much, he successfully deleted about half my codecs, leaving me with No sound at all...& without a way to get them back (bought my computer at repair place and didnt get a windows boot disk or anything for drivers, and when i asked them yesterday if they had 'em for me, the guy said "we do all that stuff on the internet"...is that wrong does n e 1 know?!?!)
2 days later, tons of searching & i now have my codecs back, and i have the exact same problem with sound i  had befor we ventured into the unknown..
does anyone know what could fix it, or if you need more system info i can post. just didnt knwo if anyone might know those signs and have a quick fix

[street1 (RIP)]

Download,install,and run Belarc advisor.Copy and paste the results in your next post.Post everything down to Virus Protection.

http://www.belarc.com/free_download.html

[Warhammer08]

here is everything except my ip address.. if you can make sense out of this and figure something out, i will be truely impressed, and if you need more info or something please ask, been 2 or so weeks this has been going on, and i hate to fork out the 100 bucks if i can fix it myself or with your help

 ;)Thanks AGAIN

Operating System   System Model
Windows XP Professional Service Pack 3 (build 2600)   No details available
Processor a   Main Circuit Board b
2.13 gigahertz AMD Athlon 64   Board: Gigabyte Technology Co., Ltd. GA-K8N Pro-SLI
BIOS: Award Software International, Inc. F3 06/21/2005
Drives   Memory Modules c,d
200.04 Gigabytes Usable Hard Drive Capacity
157.36 Gigabytes Hard Drive Free Space

LITE-ON COMBO SOHC-5236V [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
SAMSUNG SP2004C [Hard drive] (200.05 GB) -- drive 0, s/n S07GJQSP503165, rev VM100-53, SMART Status: Healthy   3072 Megabytes Installed Memory
  Local Drive Volumes
     
c: (NTFS on drive 0) 200.04 GB 157.36 GB free
 
  Network Drives
  None detected
Users (mouse over user name for details)   Printers
local user accounts last logon
 Valued Customer 11/27/2008 7:43:44 AM (admin)
local system accounts
 Administrator never (admin)
 ASPNET never 
 Guest never 
 HelpAssistant never 
 SUPPORT_388945a0 never 


 Marks a disabled account;    Marks a locked account    HP LaserJet 4050 Series PCL6 on \\DOGHOUSE\HPLaserJet4050
HP LaserJet 5M on \\SCOTTS-BOX\HPLaserJ
 
Controllers   Display
NVIDIA nForce4 Parallel ATA Controller
NVIDIA nForce4 Serial ATA Controller (2x)   NVIDIA GeForce 6800 Series GPU [Display adapter]
Envision EN-775e [Monitor] (15.7"vis, November 2002)
Bus Adapters   Multimedia
Standard Enhanced PCI to USB Host Controller
Standard OpenHCD USB Host Controller   Realtek AC'97 Audio

Communications   Other Devices
   
1394 Net Adapter
NVIDIA nForce Networking Controller
 primary   Auto IP Address:  xxx.xxx.xxx.xxx / xx
 Gateway:  xxx.xxx.xxx.xxx
 Dhcp Server:  xxx.xxx.xxx.xxx
 Physical Address: xx:xx:xx:xx:xx:CD
 
Networking Dns Servers:  xxx.xxx.xxx.xxx
xxx.xxx.xxx.xxx
xxx.xxx.xxx.xxx

   Texas Instruments OHCI Compliant IEEE 1394 Host Controller
HID-compliant consumer control device
HID-compliant device
USB Human Interface Device (3x)
Built-in Infrared Device
HID Keyboard Device
HID-compliant mouse
NVIDIA Network Bus Enumerator
USB Composite Device
USB Mass Storage Device
USB Root Hub (2x)

Virus Protection [Back to Top]   
AVG Anti-Virus Free Version 8.0
    Realtime File Scanning On
   
Missing Microsoft Security Hotfixes [Back to Top] 
        These required security hotfixes (using the 11/11/2008 Microsoft Security Bulletin Summary) were not found installed. Note: CIS benchmarks require that Critical and Important severity security hotfixes must be installed.   
Q951748 - Important  (details...) 
 
Installed Microsoft Hotfixes [Back to Top] 
.NETFramework
    1.1
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MSXML4SP2
    KB954430  on 11/25/2008  (details...)
WGA
    SP0
        KB892130  on 7/1/2008  (details...)
Windows Media Format 11 SDK
    KB929399    (details...)
    SP0
        KB929399  on 11/15/2008  (details...)
Windows Media Player 11
    KB936782_WMP11    (details...)
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    KB954154_WM11    (details...)
    SP0
        KB939683  on 11/17/2008  (details...)
        KB954154_WM11  on 11/15/2008  (details...)
    SP2
        KB936782_WMP11  on 11/15/2008  (details...)
Windows XP
    KB941569    (details...)
    SP0
        KB938127-V2-IE7  on 11/15/2008  (details...)
        KB941569  on 11/17/2008  (details...)
        KB950759-IE7  on 7/1/2008  (details...)
        KB956390-IE7  on 11/15/2008  (details...)
   Windows XP (continued)
    SP10
        MSCOMPPACKV1  on 7/1/2008  (Microsoft Compression Client Pack 1.0 for Windows XP)
    SP20
        KB943729  on 11/17/2008  (details...)
    SP3
        KB936929[SP]  on 7/1/2008  (details...)
    SP4
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Windows
    SP1
        IDNMITIGATIONAPIS  on 7/1/2008  (Microsoft Internationalized Domain Names Mitigation APIs)
        NLSDOWNLEVELMAPP