I've an 12' ibookG4 and been using it for 6 years. It's running on 1.33MHZ processor(power pc), 512 RAM, Mac OS X ver10.3. It has never crashed nor given me any problems only been lagging whenever I use Adobe Illustrator and Photoshop simultaneously. I do lots of photography and graphic designing stuff and I have huge files but it never crashed any apps. However recently I had upgraded the RAM to 726MB, that's when all my problems started. I could not save my photoshop files. Plus I had deleted much of the excess files on my pc-pics,.dmg,mp3s. Also it had prompt to clear my start up disk memory to enable the apps to function(I was using Firefox and my wireless device only). Which resulted Firefox to crash. So I did some clean up in Library and the next thing I know when I restarted my pc. Its settings had been change to the default just like when I first got it. Still all my files were intact. I did download WhatSize and AppZapper but it's unable to execute after installation. Please help! I need to know how to make space for my start up disk and make the apps work properly.