Yes, I did find that there was a window still active ater exiting that I had to close manually with Task Manager, Once I did that, I could re-run DosBox without rebooting. However, it still does not explain why, when I use the Edit Configuration Utility, the same thing happens. Dosbox is not running at all doing that and whether or not I apply the the Reset Configuration option before trying to Edit still requires a reboot for me to get DosBox to run.
As I said in my previous post this does not happen with .063 since to edit the conf file I only need to use notepad as there is no Edit configutration option with that version.
I agree this does not make any sense, but it is so and I don't know why it is happening.
EDIT: OK further investigation showed that dosbox.exe was still running after Edit Configuration was used. I used Task Manager to find this out and when I manually closed it via TM it worked normally . Nothing appeared on my desktop to indicate this, however. Very strange to say the least.