I too have had this problem. Windows 10 with all updates installed. Have manually reinstalled TT a couple of times and like previous poster says, seems to install but then insists on updating and 1603 error occurs. Have paused virus protection and read every post I could find on the subject. No difference. Sent numerous requests for help as well as the "detail log" of error to TT. No response. Please throw me a life line TT.
