Auto System Restore Points fail to create before update

Hi there
I'm not sure if this is the correct forum as I don't know if this is a System Restore problem or a update problem or a "Windows Update Agent" problem. If it's wrong would someone move it to the correct forum. Thanks
I run Vista Home Premium and I use Microsoft Security Essentials and Malwarebytes.
I have always used automatic updates and I have had no problems for about 3 years
There has always been a System Restore Point created automatically before an update
was installed but 2 weeks ago I installed an update called " Windows Update Agent"
All seemed OK until later I went to System Restore and found all the restore points had disappeared except the last one which was a Schedule Check Point for that day.
Since then I can create Restore Points manually ok and Schedule Check Points are ok
but it does not always create restore points before an update. Mostly it does not.

I have run a full scan with MSE and Malwarebytes, both were clean.
I have found if I go to Control Panel Admin Tools Services and go to Volume Shadow Copy I usually find it " stopped" I can " start " it and apply it but when I go back to it later it will be " stopped " again It is set at "Manual" but I think this is
default.
Everything else is working as it should and I could live with it as it is but I'm curious. What caused it ??? Was it the "Windows Update Agent" update install ??
Should I uninstall it ? Would that solve it ?. I don't want to do something that might make things worse. Anybody got an idea Thanks Avon