Sorry, but your post is just too brief to understand exactly what is happening. Your subject line would indicate that you either can't install or can't launch the Desktop Software. But, the body of your message then talks about BT and USB connections -- given my interpretation of your subject line, those would be irrelevant. So please clarify exactly the steps you are attempting and exactly the results from each step...including the exact and complete content of any error messages presented.
Thanks and let us know!
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.