laptop - Black screen with cursor after successful Windows 10 upgrade

Last night I tried to upgrade my Lenovo G580 laptop from Windows 8.1 to Windows 10 using the icon/reserve feature in the corner.

It completed 100%, rebooted, asked me whether to use Express Settings regarding their data collection, rebooted and presented me with a login screen.

I entered my password and clicked Enter and it gave me a black screen with a cursor. I left it for over half an hour and still nothing.

I tried pressing all key combinations. Ctrl Alt Del worked and brings up the menu, but clicking Task Manager wouldn't do anything. I was able to log out or lock the screen and could re-enter my password but still black screen. I tried plugging into external monitors and also using the Windows Key + Enter for narrator and Windows Key + P for projection settings but nothing.

I did a proper restart from the power menu, still nothing. I tried a shut down. Tried to cold boot by pressing and holding the power button, followed by a warm boot. I also tried removing the battery.

I rebooted into the advanced startup settings and tried low resolution mode, but still the same issue. Then I tried the thing about unsigned drivers. Then tried safe mode (normal), same issue. Nothing. I tried safe mode with networking, nothing. (The network side panel would show as well). I tried safe mode with command prompt and the command prompt did show.

I tried opening task manager, which did flash up the small task manager window for a second and then it vanished. Control panel won't open. None of the control panel applets. Regedit did open. "mmc" management centre did open with no snap-ins. I manually added device manager, disk management, services, and event log.

Disk management looked normal. Services seemed normal. Device manager looked okay too except a warning sign on the laptop screen (I think this is caused by safe mode). I uninstalled the drivers for webcam, bluetooth and graphics. Event log showed an error to do with a scheduled task for the browser chooser task, so I navigated in CMD and deleted this task, but on reboot still nothing.

At this point I was worried of losing my data so I went into recovery mode and clicked "Rollback to previous build" which gave me Windows 8.1 back just how I left it.

At this point I am unsure whether to attempt it again or wait. Is it possible to delete the downloaded Windows 10 and get it to re-download just in case it was corrupt or something?

My laptop is a Core i3 with Intel 4000 graphics. 8GB of RAM and a Crucial MX100 512GB SSD (replaced the original hard drive with this SSD).

I am in the UK and the laptop came with Windows 8, I got the upgrade to Windows 8.1 which went smoothly.

Thanks

Answer

I found the answer. It was because I had installed OldNewExplorer before to modify which folders display in "My Computer" and I think it was to bring back libraries in Win 8.1.

People have reported problems when explorer has been modified by things such as ClassicShell etc. Anything that modifies explorer may break the Win10 upgrade.

I uninstalled OldNewExplorer and the upgrade completed successfully.