Error Message when trying to open Turbo Tax - never have gotten into the program. Now what?

I've used TT every year for the last 12 years. Never had this problem with the CD products. Download was successful. Icon on desktop. TT is in program file on C Drive. Restarted computer. Same result 7 times, regardless of start (icon or from exe file in C Drive) - the normal start screen shows for one second to be replaced by the error message saying it has to shut down (I filled in several "what were you doing" feedback screens early on). Please help.

posted