By changing from my old Windows XP notebook to my new Windows 7 64 Bit notebook, I was forced to change from Outlock Express to Thunderbird. The *!# at Microsoft really managed it, that I was not able to import my email from the old system. ABC-Outlook my usual backup program for outlock express crashed, all other attempts failed. So I am now with Thunderbird and wonder about the high CPU usage. My new notebook has a Core 2 Duo and Thunderbird shows always with 10 to 45% CPU usage. What does Thunderbird with all this CPU power while idling?