Apple Care used to tell me but I haven't bought my MacAir yet. It was a simple solution but I forgot how.
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When you close all of an Application's windows, it does not quit. When you are finished using an Application for now, choose Quit off the File Menu. Then it will release all it memory.
try lion os and notebook forums
spec if notebook?
free up disk space
quit all apps
use lion recovery mode to repair disk and permissions
do safe boot follow up with standard boot
OS X Lion: If your Mac runs slowly
As the Hatter implies, we need more info. A PowerBook cannot run any OS higher than 10.5.8. Please do "About this Mac" from your Apple menu and confirm your Mac OS version and you processor type. The last PowerBooks were discontinued in April 2006
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