Point 1: that will not work because you have mis-spelled Microsoft in the key, it should be:
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System]
"EnableLUA"=dword:00000000
Point 2: modifying the system registry without understanding the effects can make your system unusable. So make sure you back everything up before making such a change. Also, see the warning at
EnableLUA | Microsoft Learn[
^].
If you make this change then your system will be potentially open to attack from viruses, trojan horses, ransomware, etc.