Service packs look at the application for an internal version number, and if it sees a number it isn't expecting, it returns that error you are getting. This often happens if a 'hot fix' was put in.

Hopefully there is a copy of ajwin.exe backed up from the initial installation, or perhaps in exists in the \softrak\ajwin\backup directory. In either case, replace your current ajwin.exe with the backed-up file, then try re-running the service pack install.