In the summer of 2016 I spent some days being really troubled around the problem on getting Gem working on a windows machine. The solution came with the dll file msvcr71.dll. There was also a thread called "missing MSVCR71.DLL on Win10, Gem can't load library" this spring. You might check it out.
Thank you so much Björn, this was tremendously helpful! Will try all that library moving next.
best, Peter