This may help you

declare @files table(dbname varchar(100), filename varchar(1000))

insert into @files

exec sp_msforeachdb 'select ''?'', filename from ?..sysfiles'

select dbname,min(left(filename,1)),max(left(filename,1)) from @files

group by dbname

having min(left(filename,1))<>'E' or max(left(filename,1))<>'F'

Note that sp_msforeachdb is undocumented which you can simulate using

http://sqlblogcasts.com/blogs/madhivanan/archive/2008/05/13/simulating-undocumented-procedures.aspx