How to switch from Qwerty to Dvorak or to any keyboard
Windows (2000, XP) and Mac operating systems have Dvorak and US standard 101- Qwerty keyboard drivers installed with "typical/default" installation. Guidelines to switch between Qwerty and Dvorak layout are below:
on Windows:
Click "start" button > Control Panel > Regional and Language Options > "Languages" tab > "Details..." button > "Add" button (under "Settings" tab) > in "Keyboard layout/IME" scroll down to United States-Dvorak and click "OK" button.

Key sequence to switch between keyboards: at the bottom click "Key Settings..." button > select "Switch between Input Languages" > "Change Key Sequence" button
on Mac:
Go to: apple menu > system preferences > international > input menu tab > scroll down to Dvorak