Are you following the Clean Install tutorial?
If you are and you need help, let me know - then I can walk through the steps with you.
If you haven't read that tutorial, please take some time to read through it first and ask any questions before you attempt another install.
If you plan on using the entire SSD for the Win10 install, that makes it really easy. If you have data partitions, I'll have to consider those. Also let me know if your system boots to UEFI or to BIOS.
Where is your install now, still locked up with updates?
The update takes a long time, mine sat at 44% for a while and I wondered the same thing. Then it clicked to 45% (I don't know how long that one click was, but 5 minutes might be close).
The 9926 build has a temporary Recovery workaround that is probably the reason for the time and the space.
This build creates a Roll Back because WinRE, I'm guessing, wasn't ready for the build.
My 9926 install was about 24GB, but the previous build was about 17GB. Where's the extra space going? All I can absolutely say is that 5.89 GB is previous Window data - the Roll Back. What's a GB or two when I'm rounding?