It failed twice on me using the media creation tool.  I am trying one last time with the USB stick version of the OS.  Something odd about this.  Had no problems upgrading from 8.1.  Took no time. 

I don't think it is a space problem. My 32GB 5830 has about 2.3GB free and both yours and mine appear to have stalled at the same place. The u/g calls for 5GB but mine warned me and offered to download to the microSD disk.

Maybe all we can do is hope that the u/g process reports back to Microsoft and something gets done on their side or by Dell. If it is stuck at installing features and drivers, one has to suspect it is some issue with hardware or driver compatibility. AFAIK, mine has latest Dell drivers, UEFI, ...

Same problem. I rolled back and tried again and stuck at 40% after sitting for 8 hours. This is an excellent reason why I should be able to defer updates. Luckily my other Windows (non Dell) tablet updated without a problem. I wonder if it a space problem since I only have 4.5 Gb free on my c: drive.

I Googled it a few times.  One of the "possible" reasons might be that you have an SD card installed?  In my machine, I have a 64 GB SD card and did the trick where I fooled Windows into believing that it is drive D:.  Frankly, the way I have the machine set up (programs actually installed on D:), I am not going to fuss over this.  If you want to try again, remove the SD card and try the upgrade again.

If that's the case, then I'm dead in the water - not enough space to carry out the upgrade without the microSD card. Besides, the upgrade process supports downloading the upgrade to the SD card and saving the old Windows version to it, too, so it should work.

One thing I did find through System Info was a problem device: the SXUPTP driver with error 39. It is required by/comes with D-Link Shareport Plus for connecting to a printer attached to the USB port of a D-Link WiFi router. I have uninstalled Shareport and SysInfo no longer reports any problem. The Windows 10 upgrade is downloading all over again. (Guess I should have looked into that "create media" process the first time). 

Giving it one more try.  Another post I read said something about deleting all user accounts except your main one.  I had two...so I deleted my MS account.  Left only the one I log in with.  Gonna see if that does anything.  Make sure before you run the upgrade...you delete the Windows folders that are hidden on C.  Perhaps you are getting duplicate install folders

That is a bust!  Still stuck at 40%  Installing features and drivers stuck at 23%.  Back to the drawing board

This upgrade is going downhill. First time, it said it needed 5GB on C:\ and happily proceeded when I chose D:', the SD card. This time and this may be the 3rd or 4th try because of finger fault on my part, it wants 6.62GB on C:\ and still wants an additional 2.66GB on C:\ after choosing D:\. Funny, I have 2.65GB free on C:\. Are we fighting over 0.01GB?

I am having the EXACT same issue.  Tried twice, same result. 

Called Microsoft for help.  They made matters worse.  Right now, I am restoring original DELL image back to 8.1.  If it is activated...will probably keep it.  Windows 10 is a major hassle and spyware that isn't worth the time and all this effort just to update the build