I recently upgraded RAM from 1GB to 1.5 GB.The CPU speed is 1.8 Gig, AMD Athelone. I think since then When I play downloaded songs I hear this constant hissing and crackles in the background as if it is coming from the activities going on inseide the pc case. I checked device manager, settings of speakers,volume.Checked Bios setting for the sound card,updated driver etc--Every thing shows no error no comflict of any kind. Could someone please help me to stop this Hissing & crackles in the background? My OS is Win XP (home) and sound card is SB(sound blaster)Audigy (A800).