Changing system defaults (such as search criteria in Search windows) isn't as scary as it sounds - provided you follow the rules.

WHAT YOU NEED
> Mac OS 10.4 or later

Historically, the Mac OS (or, as we old fogies once called it, its System) has given you easy ways to change most of its basic default settings - which printer to use, how windows display, whether you're warned when you empty your Trash, and so on. But in the brave new world of OS X, some settings are inexplicably buried in plist files. Here's how to hack those plist files, using Tiger's unchangeable Command-F default search criteria as an example.