Slow Download related question

I am on a permanently very slow connection download speed of 2-3 Mb/s. It takes approximately 7-8 days to do a new installation, so it’s not something I do willingly. Because I was experiencing constant crashes to desktop when launching the sim, and I could not find the cause or a solution, I decided to reset the computer and delete everything on it, and start again as if with a new PC. I deleted everything that has built up on it over 6 years of use. My expectation is that when the sim reinstalls, all possible sources of interference will have been deleted and the sim should work.
Now my question. To save myself a download time of 7-8 days in future, if there is a problem, would it be possible to copy the fresh installation, which I am at the moment downloading, to an external drive, and if needed at some future time, to copy it back to the PC (reset)? Would it work?

https://flightsimulator.zendesk.com/hc/en-us/articles/7059727103260-How-to-move-Microsoft-Flight-Simulator-to-a-new-PC-

You can make a back up copy of your game with this.