     "The file dwspydll.dll is missing or obsolete"

     One of the files used by Adding-Machine is dwspydll.dll.  There are
     several programs which use an older version of this DLL.  If you have
     one of these programs and you start Adding-Machine while it is 
     running, you will get the above error message. All you have to do is
     shut down the other program. 

     The dwspydll.dlls are backwardly compatible. You can safely overwrite
     your older copy with the one supplied with Adding-Machine.
     