Since I got currently no internet connection at home the PEAR-way of installing PHPUnit is a nope for me. So once again I had to install it manually and spend to much time on this simple task and came up with an quick setup guide. The PHPUnit source is available here.
Start to create two environement variables called PHP_CLI and PHPUNIT_HOME via the system properties(win + break keys). For the environment variable named PHP_CLI you set the path to your PHP executable and for the PHPUNIT_HOME you set the path to where you put the PHPUnit source like C:\php5.2.1\PHPUnit-3.0.3 . I keep it there because I think TDD is a must for serious web development with PHP 5 and therefor a needed core feature.
Rename the pear-phpunit.bat script to phpunit.bat and put it in your path. On my box it's suited in the PHP folder which is already in the path environment variable.
Now open the bat file for editing. Since the manual installation instructions given by Sebastian Bergmann are confusing for me and I never get it running quickly the first time, I came up with an dummy-prove solution. This is were the beforehand defined environement variables are coming in very handy. You just have to add the following line to the bat file and you'r done.
%PHP_CLI% %PHPUNIT_HOME%\PHPUnit\TextUI\Command.php %*Step 4:
At last add the PHPUNIT_HOME directory to your include path in the php.ini. Now fire up your prompt and check for the current version via phpunit --version and you should see the following output.
PHPUnit 3.0.3 by Sebastian Bergmann
Now you are ready to step into TDD with PHP 5.