I have been making a few mods to my phantom and the last ones were some new T-motor motors and Carbon fiber props. This needs a bit of tuning in the gain department and as I am still using the stock radio I can only do this via computer. Quite a few successful connections and then all of a sudden it failed to recognize the phantom. I did a google search for the issue and didn't find any solutions online other then send it back to DJI but there seem to be quite a few people that have had some USB issues. To me my issue at least seemed more like a software issue then a hardware fault so figured I would try and find a way around it, as the phantom was still displaying a solid green light when connected telling me it has found the PC just the PC hasn't recognized it. I tried manualy forcing the DJI driver on top of the one USB device that was unrecognized in device manager. This was obviously the Phantom as it went away when disconnecting but forcing the driver file didnt work here. I I also tried all the regular stuff such as different ports, uninstalling DJI Driver and Naza software. Rebooting and still no luck, then I though id try and completely eliminate all DJI software from the computer. I used revo uninstaller for this as I have used it in the past for software that's playing up. Here are the 3 programs used by the Phantom and NAZA as seen in revo uninstaller. I found that here DJI installed "DJI Driver version 1.0" "DJI NAZAM Assistant version 2.12" Both which I already tried regular uninstall/ re install with no help. I also noticed "Windows Driver Package -djiinnovations inc. (usbser)" This I though was the most likely culprit as even if I uninstalled the DJI driver and Naza this remained. So I decided to completely remove all DJI software using revo, here is how I uninstalled the last part but same process for all 3 programs. First right click on the program and select uninstall, a popup will come up saying "all programs using this driver will no longer work" select ok or yes. Once this is done do a full advanced scan Then make sure you press select all and delete to clear all remaining entries linked to this program. After you do this then repeat the process for the DJI driver, and you may as well do the same with Naza to make sure all is completely removed from your computer. Next go Back to the DJI site and install the driver and Naza software and if in my case you may be able to communicate with the NAZA again via your computer. Plain and simply USB is great when it works but a complete ***** when it doesnt, most of the connectivity is meant to be done automatically without any user interaction. So when you have a USB issue the best way to try and fix it is make sure you remove all traces of the hardware your trying to install along with any software like NAZA and try install it again. Also when installing the 64 bit driver on windows 7 you need to click ok to enable it to install the driver sfter the warning that publisher isn't identified. Then install NAZA and hopefully its all working for you, there are possible hardware faults through crashes and such so doing this wont help everyone but should help a few that are having a USB conflict issue. Also if you never managed to get NAZA to connect to your phantom you will need to work out those issues possibly make sure you have admin access to your login and disable UAC to see if that helps install the driver. This method will only help people that could connect but then lost the connection later on for some random reason and who's phantom is still showing a green light as soon as connected to your computer via USB.