CDP 5.1 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. The actual developer of the program is R1Soft. We recommend checking the downloaded files with any free antivirus. CDP lies within Multimedia Tools, more precisely Editors & Converters.
From the developer:
Continuous Data Protection (CDP) is high performance disk-based backup software for Windows Servers. After completing one initial replica of all your desired data, CDP can complete virtual full Windows server backups in just minutes. Your data is protected at the block-level and unique disk blocks are only stored once across all recovery points increasing storage efficiency of your Windows backups.
You may want to check out more software, such as Calendar and Day Planner USA Edition, Veeam Backup and FastSCP or CDPSave 2006, which might be related to CDP.