Thank you for your advices and the backround info. I just tried to install MediaWiki 1.4beta3. Unfortunatly is doesn't work too. Here's the response message: [...] MediaWiki 1.4beta3 installation Please include all of the lines below when reporting installation problems. Checking environment... * PHP 4.3.9: ok * Warning: PHP's register_globals option is enabled. MediaWiki will work correctly, but this setting increases your exposure to potential security vulnerabilities in PHP-based software running on your server. You should disable it if you are able. * PHP server API is apache2handler; ok, using pretty URLs (index.php/Page_Title) * Have XML / Latin1-UTF-8 conversion support. * PHP is configured with no memory_limit. * Have zlib support; enabling output compression. * Turck MMCache not installed, can't use object caching functions * Found GD graphics library built-in, image thumbnailing will be enabled if you enable uploads. * Installation directory: C:\Programme\xampp\htdocs\mediawiki * Script URI path: /mediawiki * Warning: $wgProxyKey is insecure * Connected as root (automatic) * Connected to database... 4.1.7-log; enabling MySQL 4 enhancements * Warning: $wgProxyKey is insecure * Created database wikidb * Creating tables...A database error has occurred Query: CREATE TABLE categorylinks ( cl_from int(8) unsigned NOT NULL default '0', cl_to varchar(255) binary NOT NULL default '', cl_sortkey varchar(255) binary NOT NULL default '', cl_timestamp timestamp NOT NULL, UNIQUE KEY cl_from(cl_from,cl_to), KEY cl_sortkey(cl_to,cl_sortkey(128)), KEY cl_timestamp(cl_to,cl_timestamp) ) Function: Error: 1071 Specified key was too long; max key length is 1000 bytes Backtrace: Database.php line 345 calls wfdebugdiebacktrace() Database.php line 297 calls database::reportqueryerror() install-utils.inc line 118 calls database::query() index.php line 516 calls dbsource() [...] Any hints? By the way: Is the import/export format of MediaWiki 1.4 compatible with version 1.3? (I would like to exchange pages with a 1.3 MediaWiki installation...) Regards Stefan