I understand this is an older topic but just reading this, it wouldnt work with a straight copy and paste:
Appevents doesn't even have a software sub folder
Anycase this would be the correct area to find the key
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
This forum seems to put a space in the reg area, not sure why but you would remove the space in CurrentVersion
You could also accomplish the same thing with a .reg file and skip the .bat step
Simply
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System]
"Disable Taskmanager"="0"
Run the .reg file and all should be good