Which JCV to Replace on Nuvi 765T

I downloaded the 2015.10 maps for my 765T. Everything seems to be going fine, but I'm confused by the JCV. I downloaded an updated JCV file, but on my 765T there are two JCV files. One is in the Garmin folder, one is in the JCV folder. Which of these two do I replace?
Thanks

I'm not so familiar with nuvi 765, but I think the jcv in the folder Garmin is wrong. On all Garmin devices, which I know is the *.jcv in a the folder JCV.

Another thing: You did not tell us which City Navigator map you want to use, but if it is the Europe, you won't have luck with the JCV on your device. All JCV of the Unicode version have a split screen JCV, but your device needs full screen JCV.

Thanks, but after I posted my question I did some comparison. The updated JCV that I downloaded was around 780K, about the same size as the one in the Garmin folder. The JCV in the JCV folder was only around 32K. So, I replaced the one in the Garmin folder. Everything seems to be working fine on the GPS now, but I am going to drive around today to see how it goes.
A good point about the maps. I installed the North America maps.

The 2015.10 map's full screen D1279220A.JCV for US & CA only [no MX] is about 780 MiB [818,553,331 bytes] so I suppose if '780K' is a typo then that's the one you downloaded.

In 765 the *.JCV file will work in either the Garmin folder or in the sub-folder JCV within the Garmin folder. However, if you leave the file in the Garmin folder it will not be automatically removed should you update maps with GarminExpress or MapUpdater and therefore the newer file placed in the JCV folder maybe will have it's correct operation interfered with by the older version still in the Garmin folder. Best to only use the JCV folder is my advice.

The smaller '30K' [maybe 30MiB?] JCV file you mentioned might be a 'full screen Lite version' leftover from another earlier map, if you post its file name we can check what map it belongs to. Probably best to just remove it anyway if you haven't already.