Just to let you know... With a bit of help from a friend, I've made the problem go away. The error message about missing VCRUNTIME140_1.dll was misleading (as computer error messages often are). Re-loading of libraries did no good, neither did upgrading to Windows 11. It was the graphics card drivers. Because I got a working display, I assumed that Windows had just found the right drivers for the graphics card. Wrong. My friend suggested going to the Nvidia site, and downloading and installing the drivers. I did, and now all is well. How a case of missing graphics drivers ends up as a error about a runtime library, I can't imagine. I hope that this message might save somebody else some time and torn-out hair! (PS - the problem first appeared on a different, older PC - could be that graphics cards that are no longer good enough for ED, as gets bigger and better, throw up that runtime error, instead of complaining about the graphics. you might need to upgrade the hardware if this happens to you,)