admin/environment/php extension/zip

The native PHP zip extension is required to let Moodle 2 read or write ZIP compressed archives.

Native installations of php will need php zip library enabling by adding the line

extension=zip.so

to php.ini

However if your php was not compiled with the extension then...

Installation on Linux Systems

If your distribution doesn't include this extension by default, then you need to compile PHP yourself and include --enable-zip.

This general PHP configuration will work well with Moodle 2.0:

./configure  --with-apxs2=/usr/sbin/apxs --enable-mbstring --with-mysql=/usr --with-pear --enable-sockets 
             --with-gd --with-jpeg-dir=/usr --with-ttf --with-freetype-dir=/usr --with-zlib-dir=/usr 
             --with-iconv --with-curl --with-openssl --with-mysqli --enable-soap --with-xmlrpc --enable-zip

Installation on Windows Systems

Uncomment this line in your php.ini:

 extension=php_zip.dll

Note: The Zip extension is built-in since PHP 5.3.x on Windows (from windows.php.net). The above php.ini line and the corresponding dll file is not require if using PHP 5.3.x or newer.