Vista - Constant ringing/hissing sound coming from my dell inspiron 1520

Does anybody know how to remove this annoying, constant hissing/ringing noise from my dell inspiron 1520 laptop? I remember fixing it before by clicking on a unknown button in my volume properties but its not there anymore.

I've also downloaded that RightMark CPU Clock Utility and it removes it but it keeps shutting down my laptop when it feels like it.

Anybody any other ideas??

Thanks

Hello sconer,
Check in the RightMark options and see if there is an option to disable the sleep/hibernation feature, this could be the cause of the shut downs, also check your power options and in "choose when to turn off display" make sure it is set to never, as for the hissing/ringing noise i would reinstall the sound drivers and see if that helps. good luck.

Hi,

I wonder if it might be anything to do with a mic or line in volume?? Sometimes, if you have one of those at a high volume level, it can cause this. Try going to your control panel and to the sound option, disable any recording inputs and see if it stops. Don't forget to show disabled devices, so you don't lose sight of your inputs once you disable them!!

As for the powering down, I can't help you with that, sorry!

Good luck!