I have an '07 24" 2.4 Ghz Core 2 Duo 1GB iMac. I am attempting to upgrade the Ram from 1GB to 4GB (2x2GB chips). Upon opening up the bottom of the case, as per the instructions on Apple's website, I find that I cannot remove the chip that is already in the machine. I was able to successfully install one of the 2GB chips, and the iMac is running smoothly with it in and registers as now having 3GB of RAM. When I pull on the tab holding in place the existing chip, nothing happens. I have looked up several guides online, which say that tugging harder will not help. Further, in the video guides I've seen, the user has had no difficulty in removing the chip with a simple pull of the tab. The new chip I have put in comes out easily by pulling on the tab. So, anyone have any suggestions? I can cope with 3GB for awhile, of course, but I'd like to be able to take full advantage of my investment.