Hey I tried to change permissions for users but it wouldnt let me tick the box to make it full control. How did you change the permissions?
You have to give permission to yourself to change that file. Windows has the permissions set to TrustedInstaller by default to prevent other people from messing with core files.
To do this, open the properties of the file you want permission of, go into the Security tab, hit Advanced (there should be a bunch of names of people with permissions), hit Change next to Owner, and a dialogue box will pop up where you can enter in names. You need to enter the name of your user. It should be like "(computer user name)\Users" and then you can check for it. Once it works and changes your name to the permission, hit apply. Then close the properties and you should have permission over the file. You can now change the Security.
As a measure of precaution, you should change it back to TrustedInstaller when you're done messing around with it.