Make IBM Notes 9 run a custom browser on Windows

18 March 2016 by Lincoln Ramsay

I have a Linux VM that I do my work in. I want links opened from Windows programs to be opened in a browser in the VM. I setup a working solution using this page as a guide (the main difference being that I use a file on a shared mount to get URLs from Windows to the VM). In case this sounds like something you want to do, download MultilevelSecurityBrowser.zip and check it out.

The problem is that Notes on Windows only has 2 browser settings. “Use embedded browser” and “Use system browser”. And when you set it to “Use system browser” it does not use my custom browser.

According to the internet, Notes 8 uses the older-style path HKEY_CLASSES_ROOT\http\shell\open\command to find the browser but Notes 9 is not looking here.

The actual registry key I needed to change was HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.html\UserChoice (Progid = MultilevelSecurityBrowser) but Windows has locked this down so you can’t change it via a .reg file. This meant I had to use the Default Programs -> Set Associations screen to change it.