Hi, I am actually researching this for my uncle who lives in Mexico. He has an old macbook...one of the white ones. I looked up the serial and its from 2009. Here are the stats he emailed me: Model Name:MacBook Model Identifier:MacBook5,2 Processor Name:Intel Core 2 Duo Processor Speed:2.13 GHz Number of Processors:1 Total Number of Cores:2 L2 Cache:3 MB Memory:2 GB Bus Speed:1.07 GHz Boot ROM Version:MB52.0088.B06 SMC Version (system):1.38f5 Serial Number (system):459279J59GU Hardware UUID:CFFAEE61-F555-5E3C-A102-CD777083555A Sudden Motion Sensor: State:Enabled He said his RAM is 4 gigs and apparently, he was told by someone in MX who has helped him with his computer that he cannot upgrade the RAM with his processor. I am wondering if this is accurate. He currently is running Snow Leopard. My first question is what is the most recent operating system that he can install on his mac without having problems? I have read that upgrading older machines with a newer OS can result in sluggishness especially if there isn't enough RAM. Second question is this: When we Skype, after about 10-15 minutes his computer shuts down. Does anybody know what this could be? I wish he could get a new machine but he cannot afford it right now nor can I afford to buy him one. Any advice is appreciated. Thank you.