Using keyboard only to login on a multi profile PC logon screen is completely possible and working. If not, it's a keyboard (hardware) error, not a Windows error.
If your account is the first one (top row left) on logon screen simply press Enter
to select your account tile, type the password (if you have one) and hit Enter
to confirm password and enter to desktop.
- Welcome screen defaults to first account, the tile displayed on top left
- Accounts are shown in alphabetical order according to the account name given when account was first created. Any later account name change does not change this order, i.e. if original accounts were Adam, Bert and Cain and you later change Bert's account name to Zorro, they are still shown in original order Adam, Zorro (originally Bert) and Cain
- If you have 1 to 5 user accounts, tiles are presented in one row. Six to 10 accounts are presented in two rows, 6 accounts 3+3 (top + bottom rows), 7 = 4+3, 8 = 4+4, 9 = 5+4 and 10 = 5+5
- Starting from default account, you can select other account tiles by using Arrow keys. Right / Left Arrow keys do not skip row when pressed at the end of the row, instead you need to use Up / Down Arrows to change the row
- On a 4 account PC, to "blindly" login to third account press two times Right Arrow followed by Enter, type the password and hit Enter
- On a 7 account PC, to "blindly" login to 6th account (bottom row second from left) press Down Arrow + Right Arrow + Enter, type the password and hit Enter