Garbled sound

hi,
i have a rather confusing problem regarding sound on my pc- can't even figure out if it's harware or software related.
for the past 12 hours, any sound on my pc (welcome note when widows open to any song or video played) appear to be garbled, choppy.
the problem seems to increase as long as the computer is kept on.
can anyone please help me, i'm going out of my mind.
this is all the information regarding my pc.
config: intel core 2 due 6300
asus p5ld2vm se motherboard
512 mb ram
creative live 5.1 soundcard
this are the things i did:
1. updated the drivers for my soundcard. didn't work
2. then i unistalled my soundcard and installed onboard audio-ac'97. it didn't work. sound still garbled.
3. in the device manager there are two yellow signs against Ethernet Controller and SM Bus Controller. apart from that everything seems to be fine.

so please someone help. thanks in advance.

 

Well, you have already eliminated the sound card and the drivers

So, I would be looking at your speakers and speaker cables next

 

thanks for your reply, shanemail.
i use a pair of headphones which i just bought a couple of days ago. just to see, if it's working properly, i uses my old headphoes in its place. same problem.
this is so cinfounding. nothing seems to work.