The archives (registers) in Germany of the noble people until II World War?

I would like to know where are today all those archives/registers kept that still had some noble people registered in times when the II World War ended.

There were noble people that were blamed to be Jews and had to show their origin and that is why I know the registers must be available. They might have come as refugees from Russia. In Russia there were a lot of Jewish people. 

If you want to "stay noble" the thing is not just that your name is in some register, but it is also up to you yourself and your family to see to it that your nobility stays "active". Some royal people, probably also of very high rank, have not been interested in this themselves, but have let the whole thing down. Now there seems to be a lot of people searching for their roots all over the world. Probably this is because the life is getting harder again and the feeling of knowing your roots gives you some security. I have now come to contact with such a name that is all the time getting more and more interest all over the world and people are suching that name, information of it and its origins in the Internet. But the archives stay closed. But to start opening graves might be unnecessary if the entry to some archives of noble people were allowed and for free!

What about registers in Hannover about noble people of old times?

Hannover Archives and various sites:

http://home.att.net/~arnielang/Hannover.html

contact this Person for any other information that he may have if you don't see what you need! Quite a Lot of Links here!