Error 500 - Internal server error (admin login not working)

I have tried all day (literally) to get this working. I am using shared hosting. Tried to read the the forums, checked the web and even had my hosting company try several times (3 tickets) and they get the same errors. This is a powerful tool, but errors are challenging.

Here is my .htaccess code in my admin folder from the main directory like /mynewproject/admin/

Options -MultiViews
RewriteEngine on

# If know that mod_rewrite is enabled, but you are still getting mod_rewrite errors,
# uncomment the line below and replace "/admin/" with your install directory.
RewriteBase mynewproject/admin/

RewriteRule !\.(js|ico|gif|jpg|png|css)$ index.php

My index.php file has not changed. I also updated the other two .htaccess files as well. They seem work fine from the browser.

Prior to this, I received the mod_rewrite error as well, so it installed just fine, all PHP tables are fine, but now I cannot login.

Actually, I figured it out after working with my hosting company and a little of my programming experience.

(I deleted everything and started over)
- I added another configuration called "Options" my hosting company asked me to add specific to them to be sure mod_rewrite works enabled ONLY on the top-most level .htaccess file
- I uncommented the line in each .htaccess file and added the path from the topmost directory to each .htaccess location - (example:

For .htaccess in the Admin folder I did this:
Options -MultiViews
RewriteBase /highestfolderfromroot/admin/

For .htaccess in the root folder I did this:
Options -MultiViews
RewriteBase /highestfolderfromroot/

For .htaccess in the install folder I did this:
Options -MultiViews
RewriteBase /highestfolderfromroot/install/

One "gotcha" I noticed was that my .htaccess file in the Admin folder was named "_.htaccess" vs ".htaccess" so I changed this too.

I hope this helps someone!