W,r,t the issue : https://github.com/NuGet/NuGetGallery/issues/760
The "user agent" header set by the NuGet client while trying to install/restore/update packages typically has the Nuget client version and OS version.
The OS version doesnt serve much purpose when we try to show data around statistics.
Instead it would be good to show details around VS version/Edition ?
Say we could know the % of users still using NuGet from VS 2010.
Note : Once the bug is fixed, please create a tracking issue in gallery to add appropriate logging for VS version info.