If you look at the solution from the link you will notice their is around 7 registries with InitialkeyboardIndicators which you need to change.
I also found 2 other methods here: https://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/559450b8-48ea-44a4-985c-c25b568cd3e1/partially-solved-rewired-keyboard-lol-registry-key-initialkeyboardindicators-never-keeps?forum=windowsgeneraldevelopmentissues
The script didn't work for me on win7 Home Premium but it look like it worked for him on Win7 Pro.
The other method is in the 2nd post which requires you to re-wire the keyboard so that the light turns on with scroll lock off. I didn't try this method since I don't want to risk breaking the keyboard and needing tools which I don't have.
Looks like I will have to upgrade to windows 10