Help uninstalling

Dear all,
I've tried to install the language Dropdown module but I'm experiencing a few issues.
After the installation everything went fine,
but when I enabled the block, Drupal has started showing just a blank page.

The issue is solved if I remove the module from my sites/all/modules directory.

I wanted to try to reinstall it to check if I had made some mess,
but now as soon as I enable it,
Drupal keeps displaying only the blank page.

I think this is because of some residual configuration in the sql databases,
so my question is:
how can I remove al tables and settings modified by language drop down?

At the moment I can't even try re-install it and check the errors because I'm not able to access my Drupal website when the module is enabled..

I'm not a Developer so I'm sorry if I couldn't be more precise but of course if you help me providing more informations to you I'll be more than glad to give them to you.
(and if it can be the occasion to learn something and help with the development I'd be even happier).

Thanks a lot in advance for your help!
Regards, Luca