2 WordPress install with same database

Do not alter any table names. In both sites (just to be sure) in wp-config.php set the WP_SITEURL and WP_HOMEURL to the related domain so these constants should be http://wow7.ro on the main domain install and http://lol.wow7.ro on the subdomain install.

See Codex.

Note that it doesn’t work for links insrted inside post or page content, because they are saved statically in post content, so in the database, and once the database is the same…

Also note that if you install some caching plugins it can brings problems…

After that inside the template you can use that constants also to conditional show content in the site:

if ( ! defined('WP_SITEURL') || WP_SITEURL = 'http://wow7.ro' ) {
  // do something for main domain
} else {
   // do something for subdomain
}

PS: in WordPress multisite means a WordPress installed with network of sites enabled, and this not seems your case.