[BUG] Claude does not spell check in english - uses local settings

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When installing Claude Desktop on Windows you need to make sure the Windows language is set to US - and also Regional settings. When Claude starts the first time that is the spell check it will use going forward.

So - if you have installed on e.g. a Danish PC with Danish Regional settings your spell check will not be corrected even if you change that setting.

What Should Happen?

How to fix:

• Uninstall Claude Desktop from add remove programs
• Reboot PC
• Remove Claude folders in %APPDATA%\
• Reboot PC
• Make sure all your settings are set to US - also Regional (clock, etc)
• Install Claude Desktop
• Open Claude and login
• Test that you now have correct spell checker in english
• You can now change your regional setting back to Denmark (or where ever you live) - worked for me.

I now have DK regional settings and US spell checker in Claude Desktop :-)

Error Messages/Logs

Steps to Reproduce

How to fix:

• Uninstall Claude Desktop from add remove programs
• Reboot PC
• Remove Claude folders in %APPDATA%\
• Reboot PC
• Make sure all your settings are set to US - also Regional (clock, etc)
• Install Claude Desktop
• Open Claude and login
• Test that you now have correct spell checker in english
• You can now change your regional setting back to Denmark (or where ever you live) - worked for me.

I now have DK regional settings and US spell checker in Claude Desktop :-)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude 1.8089.0 (ffa892) 2026-05-19T05:14:44.000Z

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_