Sounds like you need to do an "in place repair upgrade" of Win 10.  This will (should) fix the OS and allow you to keep all your existing apps and user data.  I've used this on a Win 10 corruption and it save my rear. Here is the instructions from the tenforums.com (It says you must run within Windows but I made a bootable flash drive and ran the repair from that). Repair Install Windows 10 with an In-place Upgrade | Tutorials (tenforums.com)
Great desktop computer, reliable workhorse for several years.  Runs Win 10 with all updates. Noticed Avast Free Antivirus was getting too embedded for me and I tried uninstalling the program. Avast was horribly stubborn to leave and left my system in shambles (hung boots, reboots). This started a 2+-month odyssey of problem solving starting with the hung Power On boots [Dell screen with circling marbles] advancing to the current hung Restarts.   Dell Repair (F4) found no hardware/firmware problems. Scannow found and repaired corrupt Windows files.  I tried using Dell Support Assistant for updates but I believe Win 10 hates it and the attempted downloads and app disappeared after I recovered my crashed PC. Right now I can power the system off and on but if I use Restart I'm back to the looping hang and need to use my USB Recovery thumb drive to get my system back.   I've only mentioned a tiny bit of fixes I have tried. I'm not a computer wizard. I started on the Commodore 64 and got lost after Win 7 lol. I have a system image but it was made before I removed Avast and I never want that trash on my PC again. The system is functional and I don't want to kill it permanently. Questions (if anyone is still reading this): Is it possible Dell boot programs are corrupted?  Will a Refresh repair whatever corruption might be causing the Restart problem? (Last resort for me). Should I roll to Win 11? Should I just be content with having a working On/Off system. Thanks for reading. "You're my final hope."
XPS 8930, restarts hangs after Avast removal