After upgrading on my Dell Inspiron 3647, the installation removed "Dell back-up & recovery", and "My Dell".
Also the "Qualcomm Atheros Bluetooth suite 64", saying that these apps are dangerous to the PC, and not compatible! And yet the Bluetooth works just fine?
I went on to Dell product support, but didn't see a way to replace them with Win 10 versions. The computer is out of warranty..
I upgraded 2 laptops to Win 10, neither are Dell, and it was pretty painless!
But with the Dell, I ran into a major problem that I was able to get around. The 3647 is my living room computer connected to a large flat panel older plasma HD TV using the PC input, not HDMI.
I never had a problem doing window updates in the past when the computer had to restart to finish the installation.
But during the upgrade, up until this time was fine, until the first restart.. The display never returned on the TV, and I had no idea what was going on! I ran, and got a small computer monitor, and plugged that into the 3647, nothing! I had no choice, but to do a forced shutdown.
I thought for sure that was the end, until I started it and to my surprise, I had video again, and it was restoring the computer back to my previous OS!
Apparently, after the first restart, the driver that was needed by the TV, was longer available.
The upgrade at this point, let me retry the Win 10 installation using the small monitor, and everything went as expected, except for the minor loss of those 3 apps!
Except for this last episode, I really like Win 10!