Macbook won't update past 10.5.5
I have a Mac OS X Version 10.5.8, (Processor 2.4 GHz Intel Core 2 Duo, Memory: 2 GB 667 MHz DDR2 SDRAM) I cannot get it to update past 10.5.5. When I go to update it, it says "Software Update doesn’t have any new software for your computer at this time." However, my itunes it on 10.6.3 which my computer says is the current version?? But itunes is on 11.3.... Please help! I want to not only update my computer but update my iTunes as well. My iphone will not sync with my Macbook or iTunes.