Software piracy is illegal. ConvertXtoDVD is developed by VSO Software, a company that relies on sales to fund development and support. Using a key that was not purchased constitutes a violation of copyright law and the software's End User License Agreement (EULA).
While searching for a "ConvertXtoDVD 5 key" might lead you to various "crack" or "keygen" sites, there are several risks involved with unofficial keys: convertxtodvd 5 key
If you’ve lost your legitimate key, contact VSO Software support for retrieval — they can usually help if you provide proof of purchase. Software piracy is illegal