CactuShop has been discontinued. It was old software based on the obsolete Classic ASP platform that Microsoft has long since stopped developing.
There is an upgrade path from CactuShop to Kartris, our ASP.NET ecommerce package. Kartris is free and open source. We would strongly encourage anyone still running CactuShop to upgrade for reasons of security and performance.
In addition, Kartris has far better features, is responsive (mobile and tablet friendly) and benefits from frequent updates as well as ongoing bug fixes, security and performance updates.