MS Security Patch testing
 

We want to limit our testing of MS security patches only to those applications that are impacted by the patch. What tools are there out there to determine what dlls, exes, etc are updated by a given MS security patch without actually having to install the patch?

If we have to install the patch, are there tools to scan the system before and after the patch to determine what files were updated?

I cannot find any such list of files the patch updates on Microsoft's web site.

Thanks.