If you look in Windows Disk Management you should see it listed as the System partition - this is MS speak for what everyone else calls the boot partition.

I believe it's a safety feature to keep it separate from the partitions your operating systems are on - what MS calls boot partitions.

Think the idea is if you hose any of your o/s partitions, you should still be able to boot up any other Windows o/s as the System partition is undamaged. You should also be able to make an image of it to restore in case of disaster.

Don't recommend trying a registry defrag if you have a separate System partition - you may get BCD issues.

Hope it helps

SIW2