I hope someone will have an answer to this problem. I had an Nvidia sound card which departed this life a couple of weeks ago So I replaced it (or had it replaced) with a Sound Blaster Live 24bit.  However when I plug my hi fi system into the 'Line-in'  socket I get no 'musical' sound just a noise (sounds as if it could be interference.) Nothing external i.e phone, computer, lamps, printer, scanner has moved and the Nvidia card worked fine. CREATIVE Labs suggested uninstalling and re-installing - no change after this procedure! So Help please. Thanks Tian_shiType dxdiag in the run box and test for sound..or update the audio drivers...........  Thanks for your so prompt reply - I have tried both of your suggestions. The dxdiag shows no problems - all the sounds come thru O.K. When I try to update drivers I am told that the driver I have is the best found.  The noise comes thru' on the sound card, even when the hi-fi isn't switched on, as soon as the sound card is 'unmuted'. (But only when the jack is in the socket). I have bought a new connection for the hi-fi to 'Line-in'- hoping that the problem was in that, but no joy.  
My brain is EXHAUSTED with trying to think of a possible solution - any brains better than my worn out one?
Tian-shiSee if updating the audio codecs helps.....type msinfo32 in the run box....and then click the + components then click error devices......any thing listed.....just curious....did you plug the jack plug in the right hole??Hi Merlin_2 Thank you for worrying away at this little problem of mine. I have looked at msinfo32 -problem devices - nothing is listed. My line of attack has now shifted to my sound system - I have today taken it to an engineer who can check if there is anything wrong with that. I have my doubts as it worked O.K. when I had the Nvidia sound card but as I am at my WITS end I can only try a different strategy. Thanks again Tian-shi :-/ok and good luck......thanks for the feedback.......lets us know the out come........is it the hi-fi or is it the card...Since when does Nvidia make soundcards?Raptor - That is exactly what someone else said! BUT it is true and when I searched the web initially I found that someone else had had a problem with an Nvidia card (Not that my problem was Nvidia - it worked fine). Tian-shiWell, they also create chipsets so why not soundcards. I'll be sure to stay away from them.  

Have you looked for plugs that can act as filters? They may be SHIPPED with the soundcard itself.Thanks to you all for all your help and suggestions. The sound card is working with a different Hi-Fi system !!! So - that's the first time I have heard of a sound card having a preference or not being compatible. This leaves an awful lot of But why's? in my mind Is this another gambit of the manufacturers (like regional DVD) to STOP us copying and transferring from one medium to another? Conspiracy theory - but after today not surprising Thanks again Tian-shi