500 error on activation please help

Hard to say without more details. 500 could be anything like a mis-configured htaccess file (w3tc when set in a way will write into it).

The first thing you should do is try disabling the other plugins and seeing if there is a conflict. e.g. do you have another cache app running. They never play nice since they require the same resources.

no i dont have any other cache plugins running…i tried delete the cache plugin and remove the line in the htaccess the homepage came back but the rest of the blog is 500 error

as a heads up it also adds something to your wp-config.php file if i recall. There is also the advanced_cache.php file located in /wp-content that will need to be removed.