Wow, this post has been great. Olaf you are correct in your assumptions of what I'm trying to accomplish.

To give you a little more info, I have my own dedicated server running IIS, and Wamp(apache,mysql, and PHP). It seems I could go either route. I'm am most familiar with MySql, but I'm not an expert. I also don't mind tackling the learning curve of a web service. I like the idea of avoiding "sql injections" and I do understand the vulnerablity of the mysql database if I open it for endless connections.

One of my thoughts if I went the MySql route was to limit the online database information to only suspect serial keys. This way I'm not providing the world with every single serial key I've ever had registered, and it would know which ones to block. If I take that route, I would simply have the registration info e-mailed to me each time a person registers the software. If I found a duplicate registration I would simply place that registration information in my "banned" list in the MySql database. The downside to this approach is the amount of "handwork" that's involved.

Olaf, you indicated I could create a WS using VFP, and the SOAP toolkit. Do you have any articles you could point me to regarding the steps necessary? I would like to at least investigate this route far enough to see if it's the preferable choice for the long run. I am however leaning towards MySql for ease of development.