Answer
This question was answered on October 28, 2004.
Much of the information contained herein may have changed since posting.
You could go to the Visioneer website and download the dll file your missing.
but befor you download and install the driver You must uninstall your current driver to install an updated driver.
If that does not work here are some other solutions you can try.
Choose the latest driver for your scanner, making sure to select the correct update or driver for your scanner model and operating system.
Disable any anti-virus software that may be running, as these programs may interfere with the software installation.