Backup software: We run each program through the various types of backups it’s capable of. This is largely to test reliability and hardware compatibility, but we time two: an approximately 115GB system image (two partitions), and a roughly 50GB image created from a set of smaller files and folders. We then mount the images and test their integrity via the program’s restore functions. We also test the USB boot drives created by the programs.

An online backup service isn't much use if it doesn't make the process of restoring or recovering your data quick and simple. For example, a service should offer search tools for finding particular files in your backup. It's also desirable for a service to be able to replicate an entire folder-tree structure so that it can help you recover from bigger data losses. Keep in mind that if you buy a plan that covers just one computer, you may have to transfer the account to a new PC if you ever switch your main device or if you need to restore data from a damaged computer to a replacement.

Most services encrypt your files with strong systems such as AES 256 before sending them up to the servers over an encrypted connection. The majority of products we tested also offer a private encryption key option. If you choose to manage your own encryption keys (basically the "key" that decrypts your backup), know that it is your responsibility to remember it. The online backup service itself will not be able to help you reset the password if you forget it. On the flip side, this means that no one (including employees of the backup service and law enforcement officials) other than you can unlock your backups. This is ideal from a privacy and security standpoint. Use a password manager to keep track of your private encryption key if you think you will forget it.

Bitcasa Infinite Drive is relatively new, but it's one of your favorite cloud storage providers in general, mostly because they offer virtually unlimited stroage for syncing and backups. When we say unlimited, we mean it—some of you are using terabytes of storage with Bitcasa. It's not primarily a backup service though, and while it was built for file syncing and storage, the Bitcasa desktop client does support regular file backups. Bitcasa supports Windows and OS X, and encrypts all of your files before uploading so they stay safe from prying eyes. Bitcasa even keeps revision history, so if you've backed up a file multiple times and need an older version, you can pick it out and restore it. Plus, you can use the Bitcasa mobile apps for iOS, Android, and Windows Phone to access your data on the go.