Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
It's generally best, ***** ***** installs of software, to just let the Uninstall routine do what it is meant to do, and to not delete manually.
However, that obviously did not help the problem you are asking about, and I don't think it caused the problem either.
What I suggest is:
1. that you use the Uninstall routines for *all* Blackberry software, whether working or not working at this time. Blackberry Desktop, and Blackberry Blend too. They might be interfering with each other.
2. then, when that's done, restart your computer. This clears memory of files cache etc. And can help.
3. then, from a known good reliable source - not an old CD/disc, but preferably a modern, updated, and genuinely authorized and standard source - get a download to install Blackberry Desktop, and install it.
4. and see if it works, before reinstalling Blend, etc.
Try it please. Let me know how it goes, please, also. Thanks.