Computer info:

Windows XP, SP3, Avira ANTIVIR Personal

Pentium Dual 1.61Ghz, 1Gb RAM
Gigabyte Ga-945gcmx-s2 motherboard
Soundcard currently a Crystal (Cirrus Logic?) cs4280-cm.

Some time ago, a high-pitched, non-stop sound started coming out of my speakers. I THOUGHT it was my speakers at first; changed them and still the same THING. Then I thought it was my soundcard.

Now I've just got a new soundcard (cs4280-cm), got everything set, and TESTED it. Just when I hit play in a random song the same high pitched, constant sound started coming out. It only started when I played that song, but it didn't stop when the song did. The high-pitched  sound volume is affected by Volume control, and it mutes if I mute.

So I changed soundcards and the problem remains. Any idea?I sorted this problem on my grandads PC. it was a dodgy card, obviously isnt for you, and it cant be your mobo, adjust sound settings, maybe your wave is to highIf you have a microphone plugged in, try muting the microphone in the volume settings or unplugging it altogether. It sounds like you're getting feedback from it.