Check to see if your VSS service is set to manual and set properly.

https://forum.avast.com/index.php?topic=171681.msg1218847#msg1218847
http://answers.microsoft.com/en-us/windows/forum/windows8_1-system/all-system-restore-points-constantly-deleted-with/444f41c6-1d03-4337-a18d-bcddadb50729