Hello, I found some other threads discussing similar topics, but they didn't answer this exact situation. I have OS X 10.7.5 installed on my old Macbook 3.1 (2007). Because it runs slow, i'd want to downgrade it to OS X 10.6 that was installed before. I have no Time Machine backup to the old system so a fresh install is in order. I have 2 partitions on my 500GB HDD. One is the Macbook system partition, the other is for data (music, personal files, basically everything i do not want to loose). I have to say i'm new with Macs and fresh installs so that's why i posted were before starting experimenting on the Mac and do something wrong. I just want to erase the primary (system) partition and install OS X 10.6 on it, but keep the partition table and the other partition (with data) untouched. Is it possible? And if so, how exactly? PS: I don't have a spare HDD on hand right now for backup, that's why this is so critical and i want to make absolute sure it will work before geting to work. Thank you.