I don’t know who your clients are, but if they use Windows XP, they should all have twain_32.dll installed on their computers. I am currently building a similar application in ASP.NET. If you go to your forum, you will see my post listed under the title of “Twain Web Control Issue” right after yours. What you should do, if you attempt to deploy the app over the internet (mine is an intranet with all Microsoft Based operating systems), you should run a check on the client’s computer for TWAIN_32.dll.