This is usually a keyboard layout mismatch.
If Shift + 2 gives " instead of @, Windows is likely using a layout where that key maps differently.
Try this:
- On the sign-in or desktop screen, check the language/keyboard selector at the bottom right.
- Switch to the keyboard layout that matches the keyboard being used.
- If Shift + 2 still does not produce
@, try AltGr + 2. - After signing in, open Control Panel > Region > Administrative tab > Copy settings.
- Select both options under Copy your settings to: so Windows and the sign-in screen use the same language and keyboard settings.
If characters used in other languages are needed often, Windows also supports installing additional keyboards and switching between them.