Systems, methods and media for verifying the existence of a licensed software installation at the time of an update to the software are disclosed. In one embodiment, a package of files for the update is encrypted with a copy of a key file that is contained in the original installation. The encrypted package of files is stored at a remote location that is accessible by way of a website. When a user seeks to download an update, the user must provide a copy of the key file used to encrypt the data. The user-provided key file is then used to decrypt the encrypted package.