Cant update windows 10 to version 20H2

Hello srmpinto, 

I believe you need to check upgrade logs. Refer this support article to get them:

https://support.microsoft.com/en-us/topic/log-files-that-are-created-when-you-upgrade-to-a-new-version-of-windows-9ec8aa31-0cc1-a0b2-2d98-e9c6714349b9 

Once you got these logs, share them here so that log experts can find out the cause and help you to fix it accordingly.

Hope this helps!