Ipstenu (Mika Epstein) on "WordPress Dashboard doesn't work"

Kick your hosting provider and tell them DO NOT DELETE MY FILES WITHOUT ASKING ME FIRST.

Seriously. NEVER DO THAT. I speak as an employee at a hosting company. If we did that, I would be writing up the tech and sitting them down for a lecture.

Clean out the .htaccess to just standard WP:

AddType x-mapp-php5 .php

# BEGIN WordPress

RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

# END WordPress

NOW go to domain.com/wp-admin/network/setup.php

COPY the .htaccess there and REPLACE the one you have with that one. REPLACE is the key word :) You didn't do that. I know because your .htaccess is wrong ;)