Try adding the path for php.exe and the framework’s yiic.bat to your Windows path. Then restart your system.
You may or may not need to edit the path to yiic in the yiic.php file in the protected directory (not framework directory)
in order to execute some shell options. It depends on where you installed the yii framework.
If you are using 1.1 with modules, there appears to be case sensitivity issue when generating models for a module. When the class name starts with a capitalized letter, it goes through the motions of creating the model class but no model file is generated in the module’s model directory. I had to use lowercase letters for the model name to get it to work and then open each model file to put the class name in CamelCase.