'Identifier not found' is a compiler error (not linker error) which
implies the header file which specifies upgStop() hasn't been #included in
the file from which the function is being called.
Do you have a header file which contains the declaration/prototype of
Once this is resolved, you may have linker errors isntead - as you
either need to link against the dll/lib, or load it dynamically using
"LoadLibrary()" (and then find functions within the loaded library by their