The license file needs to be in the same folder as the web page and DotTwain assembly. On XP your license file would be in "C:\Documents and Settings\username\Application Data\Local Settings\Atalasoft\DotImage 6.0".
What error do you get? Is it a web page error or do you get a licensing error shown in a message box?
Be sure to check the 'TwainControl.dll.config' in that folder as well. It has a URL that may need to be updated.
Glenn Chittenden Jr.
Atalasoft Development Team