You need to download 2 files.
1 - Go to the Blackberry Website and download the latest Blackberry Desktop Software. BlackBerry - BlackBerry Desktop Software | Applications to Synchronize Your BlackBerry and Desktop Data
2 - Go to your device Supplier (ATT, Sprint, etc), and download the latest OS Software for your device.
Once you get those, and have installed them,
Go to the directory:
c:\program files\Common files\Research In Motion.....
(don't forget the "Common Files").