Thanks and let me clarify: Yes, it is a windows form application. No, my intention was not for users to download and install it, because it's a very limited version. I was planning on them being able to run it on the website once or twice, to get the idea of what the real app will do. The limited version and the real one are separate apps. From jmmc's answer I take it that I can do this without worrying about the user having the dot net framework.