Now I'm the first to admit I have little knowledge about such things but something on my multi-boot system is wiping my main OS Vista's restore points.

The only things that are new are Windows 8 Pro RTM as the 5th of 5 booting systems and the latest edition of Diskeeper Pro installed on Vista itself.

The reason I'm asking this is that people who have been around for a while will recall how those of us multi-booting XP with Vista and 7 had to do fiddles to stop XP from deleting their restore points, so am wondering if anyone else has noticed this?

I have 100gb devoted to the VSS on C: so there's no reason why restore points should vanish.

I'm not hugely worried about it but nevertheless curious.

Ignore: It was the new Diskeeper 12's automatic defragmenter that was not only preventing creation of new restore points but was demolishing any existing ones. As soon as I turned it off voila, everything turned back to normal. Strangely a manual defragmentation doesn't have the same deleterious effect nor does automatic defragmentation on the other volumes, only the one on which the software itself is installed, quite bizarre.
I've opened a ticket with Condusiv Technologies about it.

Hey Peter,

I'm trying to get a setup similar to yours, just minus the vista, I have windows 7 currently and I want to have XP on a multiboot setup.

I won't be able to do it today, but do you mind giving me a hand if I make the thread tomorrow?

I'll try but XP, especially if you are installing it after Windows 7 or on a later partition, is sometimes a bit temperamental to setup as a dual boot and I'm no expert there

See:

Dual Boot Installation with Windows 7 and XP - Windows 7 Forums

and

System Restore Points - Stop XP Dual Boot Delete