This error is a result of conflicting system files on your computer. The problem usually involves one or more copies of:


mfc42.dll


If you are getting a message when you try to open the program that says:


"A device attached to the system is not functioning. The numbers.dll file is linked to missing export mfc42.dll:6571"


Then this is because you have more than one mfc42.dll file on your system, or the mfc42.dll file you have is corrupted. To troubleshoot this, please do the following:


1) Do a Find or Search on your system for the file named:


mfc42.dll


on your local hard drive C: Your computer should show at least one of them in the folder:


C:\Windows\System


Leave this file alone. You may have several other mfc42.dll files in other folders as well. Look to see if you have one in either of the following locations:

C:\Program Files\MySoftware


or


C:\Program Files\MySoftware\DatabasePro


If you do, delete either (or both) of these files (you can do this by right-clicking it, and selecting delete). Now try to open your program again. If your program opens and the error does not appear, you are finished.


If the program still gives the same error message, follow the directions below to repair your mfc42.dll file:


Please print these directions before proceeding, as you will need to re-start your system as you follow them:


First, you will need to remove your software.


To do so, open the Windows Control Panel (START -> Settings -> Control Panel or START -> Control Panel) and then double-click Add/Remove Programs. Here, highlight your program entry for MyMailList and click the Add/Remove or Change/Remove button to start the uninstallation process. You will get a dialog box that with the options to Modify, Repair, or Remove your program. Select Remove, then click Next, then click OK to remove the application. If you are asked if you want to delete "shared files" answer Yes whenever prompted. Answer any other questions with affirmative responses (Finish, Next, and OK) until the software uninstalls. When you're done, close the Windows Control Panel .

Next, you will Rename the folder C:\Program Files\MySoftware\MyDatabase

To do so:

  1. Double-click on My Computer
  2. Double-click on the C: drive
  3. Double-click on the folder called Program Files
  4. Double-click on the folder called MySoftware
  5. Right-Click on the folder called MyDatabase
  6. Select Rename
  7. Type MyDatabaseOld for the new name of this folder.
  8. Hit the Enter key on your keyboard to accept the change.
  9. Select Yes to continue with the renaming.
  10. Close any windows that are open

Now, you will be renaming the mfc42.dll file in the C:\Windows\System folder


To do so:

  1. Click the START button
  2. Click Shutdown
  3. Click Restart in MS-DOS mode
  4. Wait for your system to re-load into DOS
  5. Type cd system and then hit Enter on your keyboard
  6. Type ren mfc42.dll mfc42.old and then hit Enter on your keyboard
  7. Type exit and then hit Enter on your keyboard
  8. Windows will reappear. If you receive a few messages indicating that necessary files are missing, just click OK to these messages until your desktop fully loads.

Last, you will Reinstall the software


To do so, open the Windows Control Panel (START -> Settings -> Control Panel or START -> Control Panel) and then double-click Add/Remove Programs. Click the Install Button, then click Next. Use the default installation settings and answer the questions with affirmative responses (Finish, Next, and OK ) until the software installs. After the program is installed, close the Windows Control Panel, and you should be able to open the program.