I am running an IBM Thinkpad Win 98 (not SE). Although the sound used to perform well, it now emits a high-pitched screech whenever the volume is up. System sounds and sound from the CD and other sources can be heard in the background, but the constant high-pitched beep does not go away. It also crackles loudly. Checked the sound control and devices in My Computer, but nothing seems awry. Any advice please? Deacon