The answer you got from Diggsey was correct, that option is for editor plugins.
I'm running Windows 7 x64 right here and it all works fine, so that's not the issue.
You need to make sure your DBP is installed correctly (ie installed not copied to make sure the registry entry is there), the compiler is in the compiler folder, with plugins in the relevant subfolders, and that you have no security issues within Windows. In other words, make sure you are running under administrator privileges.
If you have admin privileges and have installed correctly, then you need to try reinstalling under admin privileges.