A large number of the install failures we see on windows are due to people having a way too long directory path to their sim directory.
Windows has a 255 character limit for file paths, some of the files we download have quite long paths themselves and when you add in a huge directory path to the sim folder on top of this we blow the 255 character limit for paths and install failure happens.
The easiest fix to this is to just move you sim folder to a directory on the root of your drive with a nice short directory name. Or just rename it a bit to reduce the length.
Something like this (as an example) is very likely to have a failure during install as we wasted 90 characters of our 255 limit ....
c:/users/my-user/quads/my simulators/velocidrone/velocidrone windows launcher/
this (as an example) would be much better ...