LaserSoft Imaging

Hi, I just got an Epson 1640 XL and after installing Silverfast Ai 5 I began to use my scanner with Photoshop 5.5. I selected Silverfast under Import to go scan something and when SF loaded a prompt asked me for my serial number. I entered it and then pressed okay. I heard the familiar bell sound which forced me to enter Cancel which stated it would stay in demo mode. So when I scan something it comes out with the Lasesoft watermark all over the images. What do I do? I have not been able scan something without the prompt first coming out and later getting all the watermarks. Please help.

Just found the problem. I was writing the wrong serial. I was putting the Epson Serial instead of the Lasersoft. I didn't kow it had a serial of its own. Sorry.