Hi,
First, reverse any permission changes you made to system volume information and set the volume shadow copy service back to Manual.
Next, if you don't already have one, create a Windows 7 Recovery CD. Download the relevant ISO from the links below.
You should use an application such as ImgBurn to burn the ISO to a CD - a guide on using ImgBurn to write an ISO to a disc is Here. Once created, or if you already have this, insert the CD and restart to boot from it. Select the Repair option.
Select the 'Repair your Computer' option and follow Option 2 in the guide Here to run Windows System Restore.
If you're still unable to run System Restore using this method, then I'd try uninstalling Norton using the tool on the following link ( make sure you have the means to reinstall and activate Norton ).
https://support.norton.com/sp/en/uk/home/current/solutions/v60392881_EndUserProfile_en_us
When complete, restart the PC and check if you can create and use restore points.
Regards,
DP-K