Welcome to the Forum.
Are you able to let us know a couple of things please:
- What is your default web browser?
- Internet Explorer 11, Edge, Chrome, Firefox, something else?
- What email app are you using?
- The built-in Windows 10 Mail app, Windows Live Mail? Microsoft Outlook, something else?
Generally these issues arise though when the Default browser has been uninstalled, or the setting for which browser is your default has changed - which can occur on occasion during a cumulative update of the OS.
Essentially, what happens is the email application has settings telling it to open links in the default browser and what browser that is. However, if you uninstalled that browser, or during an OS update the default browser was changed back to Edge for example, then the email application will throw the error you are seeing as it cannot find the browser its expecting to use.
In that scenario, re-installing the third party browser [ if using Chrome, Firefox, etcetera, ], or manually resetting your Default browser will resolve the issue.
Another possibility is that you are using a 32-bit OS, Outlook mail, and your chosen default browser is Internet Explorer. In this scenario there is a known issue which Microsoft provided a solution for, which involved modifying the Windows Registry. That can be easily done using an elevated command prompt like so:
- Press Windows key + S key
- In the Search field type command
- In the search results right-click on Command Prompt and select Run as administrator
- When the User Account Control prompt appears click Yes
- Now in the Administrator: Command Prompt console type or copy & paste the following:
REG ADD "HKEY_CLASSES_ROOT\htmlfile\shell\opennew\command" /ve /t REG_SZ /d "C:\Program Files\Internet Explorer\IEXPLORE.EXE %1" /f
Press Enter key
- Close the console and any other open programs.
- Restart computer
Note: Only do the above modification if using Outlook on Windows 10 32-bit OS, and your default browser is Internet Explorer 11
The above allows links to open in a new Internet Explorer window. If you have a current Internet Explorer session open ( for example: you are accessing your emails using your browser ), then you can instead enter the following command which will allow the links in emails to open in a new tab rather than a new window.
REG ADD "HKEY_CLASSES_ROOT\htmlfile\shell\opennew\command" /ve /t REG_SZ /d "rundll32.exe url.dll,FileProtocolHandler %1" /f