Can I disable the "Alt+Shift" shortcut to change language in windows 8.1 (or Windows 10)?

Good golly ... spent too much time on it, but found it eventually.

It's hidding in: Clock,Language, ande Region -> Language -> Advanced Settings -> Change language bar hot keys. (the last is in the "switching input methods").

Here's a website with screenshots .

Once done, you can change or disable it. (which made me realize i have another program that was trying (yet failing) to use those shortcuts :) ).

Windows 10

February, 2021

This comment reports solution works on Windows 2004 also.

1. Press the Windows key, type Advanced keyboard settings and then press Enter
   
2. Input language hot keys (left)
   
3. Change Key Sequence... (for "Between input languages")
   
4. Set to "Not Assigned"
   

I'm going to update the subtitle date when this gets an upvote so that we know it's still relevant.

(Thanks @bugybunny, @Bassie-c, and @skajfes for improvements.)

Under Windows 10, another lazier way to achieve the same goal is to run the following command line.

"C:\Windows\system32\rundll32.exe" Shell32.dll,Control_RunDLL input.dll,,{C07337D3-DB2C-4D0B-9A93-B722A6C106E2}{HOTKEYS}