while I use my computer to do some work, (no programming stuff just like using word xp / excel xp and dw abode-macromedia products) lately I heard "1" beep sound coming from the cpu and it happen only 1x throughout the period when the computer is "on". There is nothing wrong or anything weird happened after the sound. I am using winXP pro os with 512 megabytes.

thanks for explaining to me

See if the information here helps:

Beep codes:
http://www.computerhope.com/beep.htm

thanks for the info much appreciated