On Windows 10 and probably other versions, Lightroom and Photoshop need Visual C in prehistoric versions : 2010, 2012, .. and when you install them with CC you end up with 8 versions from 2008 to 2013 in x86 and x64 ! Why such a mess ?
Because older plugins and some third party libraries are built with older versions of VisualStudio and need those older runtime libraries.
It isn't a mess - it is the design imposed by Microsoft if you use their development tools.
Thank you, as an Insider you get more interested under the hood and sent the same reflection to Microsoft. Will they move with "Windows as a Service" ?
Bravo for Lightroom that stays a remarkable tool (the others also) !