I recently had the motherboard on my Lenovo W540 replaced. After the replacement, the language bar appeared in the taskbar and stated that I had two options for keyboards - US English or Canadian Multilingual Standard.
Since I have a regular US keyboard, having CMS available would at best take up screen space. However, the Ctrl+Shift shortcut in Windows to change keyboards interfered with my daily routine and I kept finding myself having to quit and restart apps after they refused to change back to the US keyboard so I could type apostrophes.
Deleting the keyboard from the Region control panel did nothing. It continued to show in the (also disabled in the Region control panel) language bar, and continued to make me mistype apostrophes and at-signs.
Often, I run into problems with Windows 10 where the settings that control a given behaviour are duplicated across more than one control panel or are hard to find (such as DPI vs. text scaling) and assumed this was one of them. Running the control panel with Process Explorer, I noticed that it opened a registry handle to
Using regedit to look through the keys in that registry folder, I found one that correlated to CMS, deleted it, and restarted. The language bar no longer appeared and I no longer accidentally changed keyboard layouts.