What exactly do you mean with backup?
A backup taken with neo4j-admin backup?
Or a file system backup? If so was that copied when the database was cleanly shut down?
The former can be restored with neo4j-admin restore
The latter can be copied over a neo4j installation but you need to know what you're doing. In general it's not recommended to mess on the file-system without using the proper tools.
Most important are the data/databases and data/transactions folders that need to go into the new installation at the right place. Then also plugins and neo4j.conf