Do you have the System Restore tab in your System Properties?
Right click My Computer > Properties. On the System Restore tab make sure
"Turn Off System Restore on all Drives" is unchecked.

Have you checked the registry to see if you have the disable/enable option.
Go to Run and type in regedit. Hit enter.
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SystemRestore

Look for an entry in the right hand pane called DisableSR. If it is there set the value to 0 (double click it to edit the value).

If it is not there go to Edit > New > DWORD Value and name it DisableSR give it a value of 0.

Close the Registry Editor. You may need to reboot for the changes to take effect.