Missing DLL file

Helpline Q&A Directory

I have just bought a Black Widow film scanner and am having problems with Presto Page Manager. When I try to open it this message appears: 'Prestopm.exe is linked to missing export file mfc42.dll:6453.' I click ok and another window opens: 'A device attached to the system is not functioning'.

The Find tool reveals lots of mfc42.dll files on my PC. I have fully uninstalled all the Presto programs as suggested by the Presto helpdesk. This made no difference.

Black Widow does not support the software and the Presto helpdesk seems unable to suggest anything further. Running System File Checker shows no error. I have tried to replace the mfc42.dll in the Windows directory with another copy from the CD-ROM disc. That didn't help either.

The scanner works fine with other graphics programs and the other Presto programs on the Black Widow disc also appear to work. Any ideas?

This is a common and frustrating problem, which has become known as 'DLL hell'. It is basically Microsoft's fault for producing so many different versions of a system file that is used by nearly all Windows applications. However, the software developer ought to be able to provide you with a version of the file that works with its program.

In the absence of any help from Presto your only solution is trial and error. Copy different versions of mfc42.dll into the Presto Page Manager directory and try running the program. Eventually you may find one that works.

The reason is that when a program searches for a DLL it looks first in its own directory, then in the Windows directories, and then in any directories listed in the DOS path command. If the program doesn't have its own copy of the file it can easily pick up an incompatible version from somewhere else.