I'm getting the same error when it wanted to update today. I did the manual update but when you run TurboTax it again wants to do an update and I get error 1603. What is interesting is when it attempts to update it says it's 100 complete and then instantly afterward I get the Error 1603. I'm running Windows 10, Home, everything is up-to-date. The program has been loaded for 2 months, no update problems in the past. The next process will be to uninstall and reinstall TurboTax. This sure is wasting a lot of my time.
