Do you have 517 installed on your pc? If you go to the app updater in DM it should give you all the oss you have installed. Otherwise, uninstall it. If it's not in your CP, then just delete it from the RIM folder in common files as stated before.
Posted from my CrackBerry at wapforums.crackberry.com
Go to control panel>add/remove programs and remove BlackBerry Device Software. Just deleting from directory could leave unwanted items in your registry.
Posted from my CrackBerry at wapforums.crackberry.com