[HELP] 404 Page Not Found?

[Ruin]

Ok, so what had happened was, I was screwing around trying to fix Housekeeping (I am using RevCMS 1.9.9.9) I downloaded a file for class.core.php, then dragged and dropped the file into the wwwroot/app folder, then my website kept coming up blank, so I deleted all of the CMS, and I downloaded RevCMS, and configured it all, etc etc. Once I finished, I got this:

Can anybody help me?


------------EDIT----------------

I fixed the problem, I had to do a URL Rewrite.

Thanks!