Fresh Magento install and get an internal server 500 error

I did a fresh Magento install and I get an internal server 500 error.
After running the magento-cleanup tool and disabling the htaccess-file it worked correctly.
When I enable the htacces-file I get the error again so I concluded it’s something in or with the htaccess-file.

It’s the default htaccess file and even chmodding it to 777 didn’t do the trick.

hereby the solution:
IMPORTANT! Use the File Manager in the Control Panel to edit the .htaccess file that comes with the default set of Magento files. You need to comment out the following two lines (144 and 145) by inserting the # symbol in front of each line:

#RewriteRule .* – [L,R=405]