I would like to have offial confirmation of the followings initially disucssed in the thread below. I am starting a new thread because the initial thread was closed by moderator. I will take this new thread as an opportunity to address my further concerns. Thanks you for your patience and kind advice. After unsintalled TDS 126.96.36.199 by following Gavin's advice in the old thread. I did a search of registry keys and found the following 3 keys I think are related to my TDS install. For the purpose of future fresh reinstall of TDS, can these registry keys be safely deleted? Among DCS products, I am running only Process Guard 3050 at this moment on Windows XP Pro SP2. Again, thanks!