My Windows 10 does not boot after downgrade from anniversary upgrade

[Windows Central Question]

I was using windows 10 home genuine. Then came the Windows Anniversary Upgrade and I did. After 2-3 days my apps didn't start , my store won't open , and start menu does not open . So i tried everything that i can get from online and but nothing worked.
So i decided to downgrade my windows 10 to previous build and then the process of downgrading started and it done well " i think so" and and during restart the log on page does not seems to open . There is only a blue page with a round dots like windows does before starting . But nothing appears after this much .

 

[Chintan Gohel]

try to force a restart and try again
or try starting in safe mode

If you need additional help or have more questions or details to share, please join the site so you can reply in this thread. See this link for instructions on how to join Windows Central.

 

[prince14789]

I tried it twice and thrice and left the laptop for overnight but no change .

 

[Chintan Gohel]

I tried it twice and thrice and left the laptop for overnight but no change .

you might need to do a clean install: How to do a clean installation of Windows 10 | Windows Central

 

[prince14789]

Can we find the windows 10 product key by using ubuntu because i m using ubuntu right now

 

[Chintan Gohel]

Can we find the windows 10 product key by using ubuntu because i m using ubuntu right now

you wouldn't need to find the product key....