HOWTO: Change system language in Mac OS X
1) Apple Logo –> System Preferences
2) Icon ‘International’
3) Edit list of languages
4) Place ‘English’ above ‘French’
5) Logout, login
OR
5) Close international setings window
6) Apple Logo –> Force Quit Finder
7) Select ‘Finder’, Click ‘Relaunch’
http://davidtse916.wordpress.com/2007/11/19/changing-the-system-language-in-mac-os-x/
HOWTO: Clean up (speed-up) system
Remove everything in following subdirectories of Library:
Caches
Cookies
Saved Application State