restore points disappear when reboot

Hy all

I have a Latitude e4300 with windows 7 and a few days ago i noticed all the restore points manually or automatically created disappeared when i reboot the machine. I already tried many things but  none has worked. The system restore is set on. The Volume shadow copy is running. I ran the event viewer and the events 8193 and 8194 had errors. I tried to fix it following instructions on http://technet.microsoft.com/en-us/library/ee264196(WS.10).aspx but no solution. I rebuit the wmi components. I ran sytem file checker. .. It seems there is an item called DgiVecp which should be in the registry list but it is not. Would this be the cause?

Thank u in advance!