A friend has a 2007 iMac with a 2GHz core 2 duo and 1GB ram running Snow Leopard 10.6.8. He wants to upgrade from Snow Leopard because there are programs for which can no longer get security updates, like Firefox and Chrome. The problem is with 1GB of ram Snow Leopard is as far as he can go, any OS after requires 2GB. I went to the system profiler and it says it has 1 dimm of 66Mhz DDR2 SDRAM and one empty slot. I checked Crucial's sitel and they have ram that says the following which is comparable with the iMac: Specs: DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 256Meg x 64 • lead free • halogen free • for Mac I found a stick of ram that says it is 1GB 2Rx16 PC2-5300S-555-12 sitting in my drawer. My question is if the ram that I found sounds like it would be compatible. I don't want to take the chance of anything happening to his Mac, so I am a little nervous about trying out the ram I found.