Did you try to uninstall scanner program and then Re-install it again. if so and then problem is still there, my guess is the software ( scanner) is corrupt in your hard disk, or was either wasn't copied properly in the disk and other problem could be maybe you have delete a program that associate with SHLWAP.DLL, shell32.dll and that is why you got that message. There is a link between these two file (1) shell32.dll, which comes with windows and the other file SHLWAP.DLL which i think it comes with scanner, these two file operate together or shall i say they share operation. Other problem could be in your registry, and i wouldn't suggest you to go there you have to be a bit of an expert.
PS. LET US KNOW WHAT YOU DID DIFFERENTLY