I cannot reproduce the problem here, 7.56 running fine so far on win7 64bits and I have both x86 and x64 install of the 2010 version as well as a x64 install of 2015
Your stackexchange link is actually about an issue with a specific program, rather than a general issue with runtime but someone actually has an answer that is extremely well documented about the general issue.
Basically a program made to install a 32 bit dll into an hardcoded path, thinking it's a 32 bits folder, when it's 64bits, overwritting the 64 bits dll, it is said that even if you can run the executable, it may crash later on.
If both users are on 64bits system, I recommend reinstalling the microsoft runtime c++ package 64 bits, hoping it re-overwrite the dll.
