Registered where? Registration and hosting are two different things.
Also, you’re not mentioning what you’re seeing when you go to your domain. An error? An empty directory listing?
If you mean it’s registered somewhere else and you just changed the nameservers to ns1.dreamhost.com, ns2.dreamhost.com and ns3.dreamhost.com – then that could take a few days like I mentioned.
Does your domain show up under the manage domains section of the control panel?
Have you tried reloading the site in your browser after you moved everything? You might need to clear the cache, restart your browser, etc… to see the changes.
It might also be helpful to post the domain name, if it’s not something you mind making public.
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