Windows – UK extended keyboard layout

You can use Microsoft's Keyboard Layout Creator to modify your layout. Once you've downloaded and installed, do this:

1. Hit "File" and "Load Existing Keyboard".
2. Dead keys are displayed as grey - with a right-click on any key, you can assign or un-assign dead key behavior:

3. When you're done assigning and un-assigning, go to "Project" -> "Properties" and edit the description. "Name" has an 8-character-limit (for whatever reasons), so just set it to "Deutsch" and the description to something like "Deutsch - No Dead Keys" or whatever you fancy.

4. When you're done, go to "Project" and choose "Build DLL and Setup Package". On creation, it will say it has some warnings in the log file, but they can probably ignored. The next prompt will ask you if you want to open the directory the files have been written to - if you do so, you can just install your layout with one click.

5. Open Keyboard Settings in Windows to check whether the new keyboard layout has been added to Windows' list. I

Done!

This was happening for me as well, and I fixed it doing the following (was led to this solution by user9999999's suggestion in the op comments.

1. Click Start, type "ïntl.cpl",
2. Go to "Keyboard and Languages" tab,
3. Click "Change Keyboards" button
4. Click "Advanced Key Settings" tab
5. In the "Hot keys for input languages" for the action "Between Input Languages" and click "Change Key Sequence" button below
6. Remove or replace the "grave accent" mark as its trigger with a different one.
7. Click "ok" a couple of times to save and exit the dialog.