Whew! What a day! I really don't expect anyone to reply to my issues, but MAYBE there may be some benefit for Barry's next edition. And I get an opportunity to vent.
Thought today would be a good day to upgrade my DCS system. (Just did Legacy over the weekend, thanks to information on this forum.) So downloaded all the software for DCS 4.3, and the Unloader 2.3.4a, and 2.3.4b. Checked for documentation and only thing I found was in the 4.3 upgrade which has the User Manual Verison 5. And the Unloader instructions Version 23. Neither of which makes any mention of removing previous versions. After multiple attempts of Installing the 2.3.4 software and continuous error message of not being able to install due to a later version in exsistance. After 4-5 hours of hunting for other files, deleting anything I thought was similiar, redoing the downloads, I was ready to give up. I have updated DCS many times before and never had this problem. I read and reread the documents mentioned above to no avail. Was very frustrated.
Then I remembered this thread, and thought just maybe there might be a hint of something there. On the very FIRST page found the cause of my problem! Not removing the prior version with the "Add/Delete Program" function on the Control Panel of the computer. (Hope a statement gets in Barry's next edition.)
Then, the Com Port problems. Have a Radio Shack conversion cable, and always been suspcious of it. Finally got it to recognize and actually got the TIU upgrade installed. Then for the Remotes....huh.. As soon as I opened the Remote file I loose the Com Port connection. Fought this for another hour, and finally gave up.
So I now have the TIU at 4.3, a Remote at 4.2, and another at 4.1. 
So, thinking about it, think I will get a short serial cable to extend the connection point from the TIU to the extension cable, and get a new "dongle" type Serial/USB adapter. My concern is that the serial connector in the TIU may be a little loose and not making a reliable connection to the RS cable, or the RS cable may have a problem. But, I have no problem with the connection when I connect the Legacy cable to it. So with the Serial Cable extension I will eliminate all the connecting and disconnecting at the TIU.
Thanks for the opportunity to vent, disappointed that MTH didn't make any reference to deleting the prior version, and hopefully tomorrow will be a better day.
