If you already have an older version of CFL Football For Windows installed, you can upgrade to the latest version using the lates upgrade download. The upgrade version contains only the files that have changed since the previous version. Normally this will be two files: CFL.EXE and CFLMANAGER.EXE. If your version of CFL Football For Windows is quite old compared to the latest version (i.e. before 1.0), you are probably better off to uninstall the old version using Add / Remove programs in the control panel and then install the full version. To upgrade your current version:
By default CFL Football For Windows is installed in the folder \Program Files\CFL Football For Windows. On some of the earlier versions of the program, the folder might have been named just CFL or even Project1. The important thing is to find the folder that contains CFL.EXE and extract the upgrade files to that folder.
The upgrade file will have the name CFLnnnU.ZIP where nnn is the version number (e.g. CFL115U.ZIP). The filename is the same as the full version filename except for the U at the end to indicate it is the upgrade version.