changed blog address and xampp login won’t work on local

On my local xampp installation, I was trying to set my home page to index.html instead of home.html and I immediately got a server 500 error. Now my login page has changed from wordpress to some sort of login page with my theme name. I even tried removing the theme but I can’t get rid of it and can’t log in. The only new file in wordPress that I can find is .htaccess with this in it:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /wordpress/index.html/
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.html/index.php [L]
</IfModule>

# END WordPress

How can I resolve this or do I have to reinstall xampp and/or wordpress and why did renaming the blog address cause it?

Thanks
Charles