problems w/sound device

i just got done reinstalling windows xp home and everything works except for the media player. it gives me this message: "windows media player cannot play the files because there is a problem with your sound device, there may not be a sound device installed on you computer, it may be in use by another program or it may not be functioning properly". wmp worked fine before the reinstallation. i also tried to play a dvd and no luck. does anyone know how i can fix this?
thanks in advance!

i didn't know how much of this stuff i should include:

Operating System
Windows XP Home Edition Service Pack 2 (build 2600)
System Model
ASUSTeK Computer INC. A7N8X-E REV 2.xx
Processor a
1.90 gigahertz AMD Athlon XP
128 kilobyte primary memory cache
512 kilobyte secondary memory cache
Main Circuit Board b
Board: ASUSTeK Computer INC. A7N8X-E REV 2.xx
Bus Clock: 166 megahertz
BIOS: Phoenix Technologies, LTD ASUS A7N8X-E
Deluxe ACPI BIOS Rev 1011 05/20/2004
Drives
80.02 Gigabytes Usable Hard Drive Capacity
77.52 Gigabytes Hard Drive Free Space

SONY CD-RW CRX320E [CD-ROM drive]
3.5" format removeable media [Floppy drive]

ST380013AS [Hard drive] (80.03 GB) -- drive 0, s/n 5JVDA1AT, rev 3.18, SMART Status: Healthy

Memory Modules c,d
256 Megabytes Installed Memory

Multimedia
MPU-401 Compatible MIDI Device
Standard Game Port
Unimodem Half-Duplex Audio Device

Display
NVIDIA GeForce FX 5700LE (Microsoft Corporation)

 

Are you using on-board sound or a separate PCI soundcard?
Either way, my first bit of advice would be togo to the manufacturers website and download the latest sound-card drivers.

 

sorry i haven't gotten back sooner - i was in a car accident - a drunk teenager ran a stop sign and t-boned me doing around 60mph (at least thats what the cops said). just got home from the hospital. anyway, while i was in the hospital i called a tech guy to go fix my computer, but thanks for the advice - if it happens again i'll try that!
happy holidays!