I bought an Acer notebook, which has a Core i5-450M CPU. There is a high pitched noise when the CPU is idle.
I search about this problem and many laptops have this too.Like this: http://support.dell.com/support/topics/global.aspx/support/dsn/en/document?c=us&docid=0A7D5CD2E17F5125E0401E0A55176204&journalid=5D64D40BAFB211DBB6C9D3546A7F9904&l=en&s=gen#1
For thinkpad laptops, they eliminated the noise by disabling "C4 power state" in the BIOS.
But Acer's BIOS does not provide such options.
So is it possible to disable C4 mode (or any other "sleep" mode) using some utility? (like RMClock, but it's not updated to support core i series)
If there are no settings in teh BIOS then you are out of luck. Contact ACER about it, if nothing else they should at least replace it.