I used to be able to type start \\other_machine\c$ in PowerShell and Windows Explorer would pop up with a login dialog. Then I'd type other_machine\moswald and my password (the account is a local admin, of course) and I'm in.
Now both machines have Windows 8 installed, and this no longer works (the dialog re-prompts with an "Access is denied" displayed). I've verified (through whoami) that the user is named other_machine\moswald, and I'm positive I'm typing the correct password.
So what gives?
Note : This is without a domain.
Best Answer
You have to enable Windows File Sharing in the Network and Sharing Center. The next place to look is in Administrative Tools > Computer Management > Shared Folders > Shares. You can verify that the shares (like C$ and D$) exist and check their permissions. I'm pretty sure that the administrative shares (you call them root shares) are fixed and always exist.
Also note that if you're using the Microsoft Login to access your new Windows 8 machine, it won't work no matter what you do. You have to use a Local Account. (in Settings > Users > Switch to a local account)