I just upgraded to Windows 10 and everything seemed to upgrade just fine, but when I went to the new Microsoft store I was unable to login to get anything from the store. I would be asked to put in my login credentials, which I did, it would think for a few seconds, and then simply come back with an error that says, "We encountered an error. Please try signing in again later."
I can use this same username and password on other Microsoft login areas, just not the new Windows 10 store. I have also tried a couple different logins, but they didn't work either. I even tried creating a new account with an alternate email, and the confirmation email was never sent. Seems like there is something seriously buggy with the Windows 10 Store login.
How do I get logged into the Windows 10 Store?
UPDATE 8/13/2015: I FINALLY FIGURED OUT A SOLUTION! The problem seems to be with the Local Account.
1 - I followed the instructions here to login with my Microsoft Account:
Go to Start , then select Settings > Accounts > Your account.
Select Sign in with a Microsoft account instead.
Follow the prompts to switch to a Microsoft account. You may need to verify your identity by entering a confirmation code.
Your local account will switch to your Microsoft account. The next time you sign in to Windows, use your Microsoft account name and password. Your apps and files will not be affected.
2 - I then logged out of my Local Account (completely out of windows) and now in the lower left hand corner there are two accounts, including a new one showing my email address for my Microsoft account.
3 - I then clicked on the Microsoft Account (with my email address) and logged in with my Microsoft Account credentials (instead of my normal Local Account windows credentials I used when upgrading from Windows 7).
It setup my new account for a few minutes and when it finally came up, Windows 10 now recognized my Microsoft Account as connected to my Windows account, and I was finally able to log into the Windows 10 store!