Editing ProxyEnable via cmd works but not in php shell_exec

Using Windows 10. This is my current line in php. My proxy enable setting is not reflected as '1' in the registry after running this:

echo shell_exec("powershell.exe -command Start-Process -Verb RunAs cmd.exe -Args '/c reg add 'HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings' /v ProxyEnable /t REG_DWORD /d 1 /f '");

However, running the command in cmd works:

reg add 'HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings' /v ProxyEnable /t REG_DWORD /d 1 /f

Does anyone know how to set ProxyEnable to '1' via php shell_exec?