Install PHPUnit

Install pear on windows
You probably need to do a very simple thing.

C:\>xampp\php\go-pear.bat

if not upgraded then use "pear upgrade-all"

Install pear on Ubuntu
Install: sudo apt-get install php-pear
update its own channel: sudo pear channel-update pear.php.net
upgrade: sudo pear upgrade-all

Now proceed with below steps

1. pear channel-discover pear.phpunit.de
2. pear channel-discover pear.symfony-project.com
3. pear install phpunit/PHPUnit