Is my business still registered?
The answer really depends on what kind of registration it was. If you registered an LLC, corporation, or any other legal entity, then you can look it up in the state database (usually on Secretary of State, or another state agency in charge of entity registrations).
If you are talking about a fictitious/assumed name (DBA), then looking it up would depending on the state, county or town where the DBA is registered. For example, in Oklahoma or Ohio the DBA is registered with the secretary of state, and can be looked up the Secretary of State website. In New York or Texas it will depend on whether your DBA was registered for you as a sole proprietor (or partnership), or as another trade name for a registered legal entity. Finally, as another example in Massachusetts the name is registered with the town clerk.