I have a Windows 2K8R2 machine with two hard disk (1: 50GB, 2: 120GB). Both disk have a MBR partition (no GPT

When I try a Windows Guest File restore (Veeam B&R 6 patch3), I see only two disk (C: which, in fact, is the boot parition of 2K8R2, and D: wich is the real C:) out of my three disks. D: is missing (the 120GB disk, should be E: when restoring).
When I try a "Other Os guest file restore" via the FLR, I can see the E: disk.
Do you have the answer ? I must explain that behaviour to the end user (one of our *big* client).