CCE reboot, startup repair started.. new OS? Partition issues please help

Hi, just registered.

I installed and ran CCE. It downloaded a virus definition, asked to restart…

I’d scheduled windows test mode, to try and sign a driver (PCI Latency tool). I cancelled this, and allowed the reboot…

A startup repair began. I’ve already lost one partition (extended, 50g, just disappeared after perfectdisk did some scheduled ‘smart’ task in the background) and now I’m worried my OS is on the brink…

The computer rebooted (fast) straight into windows (no user name / pwd)

My System… doesn’t apppear to be loaded. diskmgmt.msc shows the partition (and new ones) but … I don’t want to touch anything else. I don’t know what I’m doing.

The C drive is a virtual hard drive (300gb). It’s installed on ‘barebones’ (native VHD, using diskpart).

My “new C” is only 16gig.

Does anyone know what happened (coincidental MBR corruption during CCE reboot to … search for rootkits?)

Can anyone advise which tools / commands to run to restore my OS?
Currently it’s booting into a “new OS”

Concerned J