If the Send optional diagnostic data is not turning off, there could be an organizational level configuration at play here.

How to create a Windows Diagnostics and Recovery Toolset image Your email has been sent Create a DaRT-enabled recovery image for either a USB drive or optical media ...

Microsoft Diagnostic & Feedback data offers two settings. Basic and Full. If you want to turn off recommended troubleshooting, the only way out is to stop it from collecting complete data from your ...