System Settings

Template:I18n/Language Navigation Bar Systemsettings is a program where you can configure many parts of your desktop. Color, style, shortcuts and many other things. It takes the place of KDE3's kcontrol. Its principle groups are

On the General Tab

Look & Feel

Appearance
Desktop
Notifications
Window Behaviour

Personal

About Me
Accessibility
Default Applications
Regional & Language

Network & Connectivity

Network Settings
Sharing

Computer Administration

Date & Time
Display
Font Installer
Joystick
Keyboard & Mouse
Sound

On the Advanced Tab

Advanced User Settings

Audio CDs
Autostart
CDDB Retrieval
Desktop Search
Digital Camera
File Associations
Input Actions
KDE Resources
KDE Wallet
Service Manager
Session Manager
Solid

System

Login Manager
Samba
Task Scheduler

If you can't find a setting that used to be in kcontrol it is very likely that it has been moved to the Settings section of the application concerned.