Are you trying to recover data from a or just accidentally deleted files?
The Professional version is often offered as a free trial download. This allows you to scan your drive and preview recoverable files for free, but you will need an activation key to actually save/recover files beyond the 1 GB limit. Key Features of Version 9 Professional Stellar Data Recovery Professional 9 Free Download
Restores lost or deleted files from internal/external HDDs, SSDs, and SD cards. Are you trying to recover data from a