Install phpBB fails, sort of

[GearHead]

I go to Install Central and click on the install for phpbb
state the directory as www.mysite.com/forum
select my Db
Assign username/password
- States install successful
- Per my ftp software, files are showing.

go to any of the pages and I get 500 Internal Server Error
-- The server encountered an unexpected condition which prevented it from fulfilling the request.
The script had an error or it did not produce any output. If there was an error, you should be able to see it in the error log.

What am I doing wrong?

[Croc Hunter]

What is your domain name? FTP in and delete the install and contrib folders/files.

[rtoohil]

What is the error in your CGI error logs? Have you turned on CGI?

[GearHead]

Here is the CGI error:
"Fri Jan 5 22:46:53 2007] [error] (2)No such file or directory: Apache::SubProcess exec of /usr/local/users/pow/a/n/pow.antpress/php/php failed"

There is no install folder to delete.
My domain is: www.gearhearacing.com

[GearHead]

Got it working, I don't know what I did differently...