I struggled with this last year, my subject in this Forum on this was:
"Windows 10 Creator Update 1709 hangs at 33% during reboot"
I also paid Microsoft for support and the remote people made me glad I had backed up my system as I had to restore it after they got done mucking it up to the point that it was useless.
I took my Dell XPS L501X laptop to the local Microsoft store and their experts worked on it for three weeks. Their conclusion was that my Dell NVIDIA graphics drivers were not compatible with the 1709 version of Windows 10. It works fine with the 1703 version. I worked with NVIDIA to get the latest drivers for the graphics device with the same results. What I have discovered is that Dell (and maybe other computer suppliers) have no incentive to make their computers capable of working with the latest versions of Windows 10. Maybe collusion to force us to by new computers? The best Microsoft was able to do was set my Microsoft update to only update the 1703 version using the Group Policy Editor and not force me to accept the 1709 which always crashes. I was really impressed by the local Microsoft folks.
Microsoft's advice was to wait till 1703 is no longer supported and try to upgrade again and just maybe there will be a fix in the software/hardware and good luck.
Dell's advice was to buy and new Dell laptop and discard my top end (and expensive) XPS L501X, I really have to question why I would ever buy another Dell.
I have several computes that work well with the 1709 update, just not my top of the line Dell XPS.
All the advice to "clean up" and "do a clean install" on my Dell XPS were attempted by myself and the experts at Microsoft with the same results. If you are unlucky and have a computer that has an inherent incompatibility with the Microsoft 10 version that is failing and your computer supplier is not supporting you try to set your upgrade policy to keep you on the 1703 which is supposed to be supported for quite a while. And good luck.
Just a suggestion, have you tried to disable the ‘NVIDIA GeForce GT 420M’ (that is the problematic thing for the update) which comes with your Dell XPS L501X? Does your Dell come with the ‘Intel Core i5-460M (BGA) CPU’? If it does then you can switch to the integrated GPU of the i5-460M which is an ‘Intel HD Westmere’ that came with only one specification of 12 execution units, up to 43.2 GFLOPS and at clock speed of 900 MHz (which is pretty much equivalent to the 'Intel HD Graphics Tier GT1’) but, it’s not as good as the ‘Intel HD 3000’ which is a Tier GT2 Intel graphics (that I have in my Aspire 5750) but, its adequate as a graphics emulator. Then, try to update your Windows 10 with the 'Windows 10 Creator Update 1709' with the Intel graphics as your primary graphics, as I’m sure that the update will work then switch to the ‘NVIDIA GeForce GT 420M’ and see if that works. This is how you switch between the two GPU's:
To select NVIDIA card or Intel card
1. Right Click on Desktop
2. Select nVidia Control Panel
3. In left panel select "Manage 3D Settings"
4. In right panel select Global Tab
5. Under "Preferred Graphics Processor" select "Auto-Select" for NVIDIA or "Intel" and hit APPLY button
*Now try again and see if it properly selects correct GPU.