Insatllation issues

[chook]

Hi all.
I uploaded all the files and folders a couple of days ago using FileZilla.
My site is hosted on www.siteocity.com :
MySQL version 5.0.90-community-log
Apache version 1.3.42
PHP version 5.2.13

This is the error message that I receive when trying to run the install URL.
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, [email protected] and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Apache/1.3.42 Server at www.oasis-agencies.com Port 80