B&R and open files

[eagle111]

I have 2 hard disks in my computer both of 1 TB
I have made a mirror (using B&R 10) of disk 1 (to an external disk) and that went ok
I tried to make a mirror of disk 1 (incl c: with windows) and it fails
I tried other partitions on disk 1 and that also went ok
when i try to mirror disk 1 and partition c with windows and all programms it fails
I think it has to do with open files
Could someone explain to me how to avoid this problem

[Paragon_Matt]

Open files aren't normally an issue, would you please clarify what error you are receiving with the Paragon BR software when attempting this.