If you see a We can’t sign into your account message when you sign into your account on your Windows 10 PC, then this post may be able to help you. In the message dialog box you will see the following explanation:
This problem can often be fixed by signing out of your account and then signing back in. If you don’t sign out now, any files you create or changes you make will be lost.
We can’t sign into your account
If you face this issue, here are a few things you could try.
1] Restart your PC and see if this makes your problem go away.
2] Create a new user account and see if you can move your data from the problematic user profile to this one. If you can do it and if the new account works fine for you, you may use it as your main account. If you wish you can add your Microsoft credentials to it and use it as your Microsoft account too.
3] Run the Microsoft Account Troubleshooter and see if that helps.
4] Use System Restore to restore your system to a prior good point and see if that helps.
5] If you are signed in with a temporary profile, you may see the following popup.
You’ve been signed in with a temporary profile. You can’t access your files, and files created in this profile will be deleted when you sign out. To fix this, sign out and try signing in later. Please see the event log for more details or contact your system administrator.
In that case, this post You’ve been signed in with a temporary profile is sure to help you.
6] ReProfiler is a freeware for manipulating User Profiles on Windows 10/8/7/Vista/Server & useful if you are unable to access a User’s data and settings. See if this tool helps you.
Hope something helps.