Why can't I upgrade Windows 7 to Windows 10

When you are upgrading to something 3 versions newer simply installing drivers ahead of time simply won't work. You have to take into consideration compatibility issues first! With a clean install you would download but not install drivers on the spot but wait until the newer version is up and running first. The old "Rule of Thought" that applied to previous versions as far as downloading updates ahead of time doesn't seem to apply to 10 since that seeks out and downloads, installs the latest in most cases automatically and why even the tv tuner card here that waited a year(on Windows 7) with the first card(died along the way and was replaced back in 2011) for Vista 64bit updates was found working immediately with the upgrade to 10.

As for av softwares in most cases the upgrade install tends to see the av program removed as the set up is conducted without the desktop and apps even running. The av or firewall interference would be seen when trying to start the Setup.exe file manually not when booted live from removable media. The 2014 version of the AV software wouldn't even go on 10 when at first having sought out the 2016 beta(the finished 2016 version is now available) until the first clean install saw the 2015 version go on that.

Now as for seeing the C:\users folder become D:\users the request for a snipping view of the Disk Management tool to see how the drive(s) are layed out will be needed here to see why C is only 40gb in size with only 7gb free. Is that on a drive split up into multiple partitions which it sounds like not leaving enough space available for the OS primary which is preventing the upgrade to begin with?

Well the problem is the 10 installer locates drivers often 8.1 in particular for things like the chipset and video card as well as other expansion cards actually picking up the wrong driver for the PCI tv tuner card discontinued model that originally saw only 32bit XP and Vista support until 7 was in beta. I ended up replacing fhe first two cards and so far the 3rd has held up, The 8.1 driver and app for a newer PCIe model apparently using the same chip went on and worked like a champ!

The Creative Console Launcher was a nice find lately when going to Creative to locate the 8.1 update and a no go until finding the "Unofficial" driver/app release on the forums. The driver pack and app bundled up is not supported by Creative at all but brewed up for those trying 10 and being stuck!