My computer died and I’ve reinstalled Arizen but I don’t have any backups. Are all of my ZEN lost?
Yes, they are. Arizen wallet is not a web based service. For recovering your wallet you need to have the *.awd or *.uawd wallet files or a backup of the private keys.
There are some 3rd party services / software out there for file recovery from hard disk failure or formatting, but often, it comes at a steep price. Recovery of data from a solid state drives that was wiped will not be possible to recover.