Thanks for your replies guys - this problem's giving me a serious mag drop!
I've tried playing music in Real Player and WMP but still have the problem.
The speakers are standard esktop jobs and the problem is replicated using headphones in the same socket.
There is a socket on the CD player itself but I'm as yet unable to get sound from it.
The card isn't the ATI Radeon - that's the 3D card only. The sound is through an ESS Maestro PCI card. The drivers are deffo OK as it used to work fine.
There are no erroneous inputs - I've disabled the mic.
The PCI modem is installed but not used - I've got a broadband modem (external, USB) and the problem was around when I used the internal dial up modem.
It just just had a sense of humour failure for no apparent reason.
I've also done a defrag, virus scan etc but to no avail.
Arghhh!!!
PSP
London