System Restore is not configurable

Hi Everyone,

I am using Windows 7 Ultimate x64 and my System Restore functionality is not working. When I try to set the drive space to be used by System Restore Points (Start > Right Click Computer > Properties > System Protection > Configure), I am met with the following messages -





System Restore has worked previously on my computer (now about 2 years old), however I recently made the decision to manually delete all of my existing Restore Points, and shortly after I started to see these messages.

If anybody knows how to overcome this challenge can you please share?

Kind Regards,

Davo