Drupal installation not even starting - either Internal Server Error or Access Denied - might be .htaccess or httpd.conf problem

Hi everyone!

I am currently trying to install Drupal (currently testing some alternatives to see which CMS is the most suited for a bigger website I am planning to launch). For this, I am using a dedicated user on a vServer (in this case web5). The vServer is already running a website on Contenido and an ActiveCollab project (obviously different user and hence directories etc. - one is web1 and the other web2 - so they don't share the same webspace with Drupal). All the other PHP/MySQL programs run fine, but I am just failing to get even the install-script of Drupal to start.

I've followed the installation instructions and then tried to open the installation script but all I was getting was a 500 - Internal Server Error. I then looked around in this forum and started playing around with the .htaccess file. One thing I have done was to comment the following:

# Don't show directory listings for URLs which map to a directory.
# Options -Indexes

# Follow symbolic links in this directory.
# Options +FollowSymLinks

This resolved the Internal Server Error - which is now being replaced by the following message when I try to open the install script:
Forbidden

You don't have permission to access /drupal/ on this server.

I've then tried to find a solution in this forum for the new error. I tried to link the domain directly to the folder Drupal is in but the only thing that changed was that the path in the error message said / instead of /drupal/. I also recursively set everything in the Drupal folder to 777 but that didn't help either (already reverted this to the original permissions). I read somewhere else to try with some parameters to specifiy the web address and the server path, but that just evoked another Internal Server Error.

I even tried to just delete the .htaccess - but that only causes the Internal Server Error to come back, so that didn't resolve my issue either. What is really weird is that I am running other PHP scripts (and ActiveCollab is a relatively complex one) without any problems, never had an Internal Server Error...

So basically, what I am thinking is that I still might have to change something in my .htaccess and I often read that sometimes modifying the httpd.conf helped to resolve such issues, but I honestly don't really know what exactly to do know and I therefore hope to get some help.

Thanks in advance!

Alex