Hi
Have just installed the free latest version and instantly brought my site down- front and back end. Can anyone please help me uninstall it or fix the problem as I am now in big trouble.

Thanks

Do you get any error?
Do you see just blank page? If so, check the webserver error logs and look for error there.

It is possible your server does not support mod_rewrite and presence of .htaccess file may block the site. You may try renaming it e.g. to _htaccess.