If you are a BlackBerry Enterprise Server user, do not install BlackBerry Desktop Software before consulting your administrator or referring to
Next Steps after successful download:
1) Click on Save.
2) Close the BlackBerry Desktop Manager software.
3) Double click on downloaded executable file.
4) Click RUN on dialogue box.
5) Choose Setup Language from the dialog box
6) Install Shield will install all required modules on PC/laptop.
7) Allow the BlackBerry Desktop Manager software to restart at the end of the installation.
System Requirements can be found here