Remove All Ram except for 16 gigs then try reinstall clean.

Once thats installed install 7zip

https://www.7-zip.org/download.html

Then download the Driver Cab

https://www.dell.com/support/kbdoc/en-us/000121822/

Move driver cab to my documents folder.

Right Click the cab file and with 7zip say extract here.

Then scan device manager to update and say find drivers from my pc not from the internet.

There should be no yellow ! and the intel drivers should be in AHCI mode as well as the audio drivers should not be generic HD audio drivers.

EXTRACT HERE

Thank you for your quick reply. I tried with 16 gigs (I have 64) It still crashes at the beginning . One second of windows logo and black screen (and a line of pixels on top in about 10 seconds) and restarts by itself after that. I tried again with a USB fresh install of version 1909, that works fine, so something changed with this 20H2 update. I will mention again that I tried with windows update assistant, that gave me an error of 0xC1900101. I also tried different partition schemes and file systems when writing the USB with Rufus. GPT+Fat32, GPT+NTFS, MBR+NTFS. In every case the Windows 20H2 installation crashes  in the beginning. The MBR+NTFS was the only one that gave me an error code  (a memory error): 0xc0000017.  

I was thinking about a RAM problem but I tried with less RAM, with one, two, a.s.o. I also have a windows installed (version 1909) on the T5600 that works perfectly fine. I tested it many times successfully with DELL assistant. 

Hi Axel777

I am having the same exact problem and I've tried everything i can think of. Did you find any solution on your problem? I'd appreciate if you could help me.

That is a Windows installer driver update stage bug.

You should download the offline update package, or make it with the media creation tool. then execute it from a command line as:

setup.exe /dynamicupdate disable /migratedrivers none /telemetry disable

The reason is that the offline package is not really 100% offline. After extracting files, it tries installing updated drivers, and contact MS server for telemetry and other spying reasons.

Both may fail. The command line switches disable both. But you will need to update some non-working drivers later manually.

Good post @Andy812  .

I think you might also be able to do a local overlay/upgrade install from the Installer-USB (made with Media-Creation-Tool).

Only thing is ... be sure to disconnect machine from ethernet-wire and/or WiFi-Access Point (totally offline during install/upgrade).