Some PHP files will load in my localhost folder, others will not

Usually this happens with .php files that I've moved in from other folders. Right now I have a few test pages that load just fine when I open them, but others (such 开发者_StackOverflowas the Joomla files I just moved in) do not load... there's only a blank screen. I've checked on the permissions and I should be able to edit and view the files. Oh, and I'm using Vista.

Can anyone think of anything that might be causing this? Thanks.

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Did you move all of the Joomla files in, or just some of them? Did you properly configure Joomla? What web server are you using? Does your web server have permissions to view and/or edit the files?