If you would like to manually remove or inspect the client side installations made by Dynamic Web TWAIN you may follow the following guides for various browsers.
Internet Explorer 10/11, Edge, Chrome 27+, Firefox 27+
On Client machine look at Control panel-> Programs and features ->look for "Dynamic Web TWAIN HTML5 Edition" or Dynamic Web TWAIN HTML5 Edition Trial"
Internet Explorer 6-9 (and 10/11 if ActiveX is forced or emulation mode is used)
in IE > manage add-ons > show all add-ons -> Look for "Dynamic Web TWAIN Class" or "Dynamic Web TWAIN Trial Class"
Firefox < 27
Go to add-0ns -> plugins ->Look for "Dynamic Web TWAIN Plugin" or "Dynamic Web TWAIN Plugin Trial"