What's my username? I get rejected

I recently installed Windows 10 on my machine and I'm not sure what my username is. I don't remember being asked to provide a username. I'm trying to sign in using my Android tablet to get access to files that I've set to be network-shared. I've tried my full name and my e-mail address which are both visible at the Windows log-on screen. I've also tried 'Administrator'. Every time I do this, the box on my tablet just clears, suggesting they were rejected. I know my password is correct because I've locked and unlocked my PC. Is there a log file I can check to see what Windows is doing rejecting my authorisation attempts? This worked fine on my previous Windows installation/motherboard so I think the Android app (ES File Explorer) is fine.

A full username you need to use in networking is made of your computer name and user name (ComputerNameUsername). You can use this name to sign in to network resources regardless if your Windows user account is a local account or a Microsoft account.

Below a bit longer reply, but I thought this might benefit some future readers with networking issues, too.

Using a local account, knowing your username is simple: it's the name you selected when setting up Windows with a local account. Using a Microsoft, domain or Azure AD account it might be and often is different than the part before @ sign in email or domain username.

Using myself and this computer I am using at the moment as an example, I sign in to Windows and check my username. Pressing Win + RI open the Run dialog, type netplwiz and hit Enter:

This opens a so called Advanced User Control Panel, in which I select my user account which in my case is a Microsoft account and click Properties:

This shows my "real" username:

OK, now I know that username is Kari. In my example case now it was quite obvious, but if your name on a Microsoft account email address is for example longer it will be a five character abbreviation.

Next I press WIN + Xto open Start context menu and select System:

System Information(Windows 10 version 1607) or Windows Settings > About (Windows 10 Insider Preview) opens. I can see this machines computer name is W10DESK01.

System Information:




Settings > About:

That's all the information I need. My full username to access this computer over remote desktop, or to access its shared network resources from any other device on my network is W10DESK01Kari. My password will be my Microsoft account password

As long as file and printer sharing is enabled on Windows computer, this username with correct password will let me access it.

Kari

Thanks very much. I'd never have determined that my username was "Seanv" on my own!

Thanks very much. I'd never have determined that my username was "Seanv" on my own!

You are welcome.

Your username Seanv hints that you are using a Microsoft account with an email addresssean.vxxxxxx@any_email_provider.com. When the name part of an email address is more than five characters, Windows creates a five character abbreviation of it.