Vista - implementing security templates

Hi,

I am juan from argentina.

I have a task of implementing some bestion hosts in the DMZ so im
implementing windows 2003 servers with the most tighten security
template from microsoft.

the problem is that after I implemented the template nothing worked so
I tried to roll back to setup security.inf which is the default
security policy and still nothing workrd ! so like a stupid, I had to
reinstall the server...

I have two questions:
1. was I doing something wrong?
2. is there a tool which tells me why the application cant run after
the implementing the security policy? maybe a tool which tells me that
this or that registry key is blocked or a spacific registry key doesnt
have enogh permissions etc..?

thanks a lot !

Juan