After supposedly "successfully" installing Windows 10 two nights ago, I immediately encountered a problem experienced by many who have posted in the forum.
A search will yield you many similar stories. But in an instance like yours, basically you'll find that...
- After sign-in (but before the boot-up appears complete), the computer just hangs there and becomes unusable and inaccessible.
- The screens "flickers" (flashes) back and forth from black, to an empty desktop, to a desktop with icons, and so on all over again.
- The computer seems stuck in a never-ending cycle or some unknown process.
- Being able to access only the Task Manager, CPU and/or Disk usage can be witnessed running at 100% intermittently.
Responses to these posts vary. Many have successfully resolved the problem. Other sit patiently awaiting their solution.
Many also call for the user to enter Safe Mode. From there, you can choose to Troubleshoot, fix things, or simply uninstall Windows 10 altogether.
In my case, I chose to the "Go Back To Previous Build" option, thinking this was the safest bet.
That was 18 hours ago.
The computer is still "Restarting...".