I am now experiencing the same issue. And I can replicate it.
re-install construct 2 stable version r212 from any of the other versions and from installer try to run construct 2.
[quote:2cs7qvnv]Unable to execute file
CreateProcess failed; code740
Need to elevate permissions to run this file/program
I can bypass this my elevating permissions, but definitely something wrong with R212. It seems to only trigger once you try downgrading or upgrading from another release.
Same as OP, windows 10 64bit, etc.