copied from that post listed above. a mod may want to post it elsewhere for more coverage.
Thought I'd pass this on as it has been causing me a head-ache which can't be resolved, even with a lot of pooled experience amongst my colleagues in the business, lots of technical group searches and calls to Garmin .
So, the new Windows 10 update has increased security - a lot. It now uses cloud based technology to filter malware as well as a host of other security measures. The problem is, it now blocks any plug-in drivers from being installed if they aren't certified and installed in a specific way - which most aren't, including Garmin Express.
If you already had Garmin Express working before the Windows upgrade, it should still work, however if you try and install it after, it will still update the maps on your unit, but it won't let you install the maps on your PC; the button is "greyed out" because the plug-in has been blocked.
I've tried everything, including manually disabling all the new Windows security, cleaning Garmin Express from the computer manually and reinstalling it in admin mode - it still gets blocked
So if you find yourself in this position, I'm afraid that there is currently no solution other than to wait for the Garmin developers to release a fix (which I'm told they are working furiously on now). I managed to get a work-around by manually copying the installed maps from my laptop's internal drive to my desktop, but if you don't have multiple computers that may be a problem and it's not that easy to do if you don't know how to copy over and edit registry entries.
Hopefully this might save someone some pain anyway...
PS, I'd recommend you don't run any third-party anti-virus with the new Windows update. Normally Anti-virus disables the built-in Windows protection to prevent doubling up and the resulting problems and slow operation, but until the other vendors have caught up with the new windows structure there could be unpredictable results. Also, the built in "Defender" protection is now as good or better then third party offerings - and free, so I'd just use that