Go to joomla.org, download the .tar.gz archive ... upload the file to your public_html, unzip using the filemanager ( if LunarPages File Manager has this option ) and then follow the steps ( it's easy ).

Here you go, one video tutorial on how to install Joomla 1.5.x: http://help.joomla.org/ghop/feb2008/task167/joomlainstall.html ( ignore the first part when they set up xampp, you'll follow the tutorial from the middle ... when they get to the "Chose your language" part ).

Also, you can ask for your money back and find another company that offers cPanel.

Thanks for the responses, just checked them, I also left out a little detail as well.

Late last night while I did download the full package and upload from Joomla's website, i also tried to install SMF and a couple other webapps, none of them worked. I did however upload a simple static page, works just fine.

While I put construction page up, I also tried installing it to folder and tried reworking the configuration.php by testing using a test.php from a page in here by Mitch. All resulted in the same Internal error.

Again I ask what's the deal with LPCP having an older version of Joomla vs Cpanel for fantastico scripts? Do I have to get the owner to pay $2/month just to get Joomla??

Also I am only asking for help here, because I just purchased account and the support counter isnt open yet since I'm on the East coast, did not know of that Operational change.

Ok i sent email and ticket, just to let you know, I did another installation of joomla with same problem, but this time the configuration.php file cannot be changed.

And in comparing my joomla site to the new one, in FileZilla it shows that i have owner group access to the file on my site, the new one doesnt give that access... may have spotted the problem like you said Katrina. Will create a new install and hope tech support can resolve.