I need help fast!

I intall a Jgallery mod and now cannot get the admin login screen to appear. I delete all the file of the mod and still cannot get to the amin. I get a "404 page not found" error.

I need to hang this project in by tommorow and now it blows up on me!!!

The strange thing is the mod didin't override any files sod I am confuse why the admin is not showing up.

HELP PLEASE!!