Backup exec 2012 + SDR on local USB Disk

Hi all,

i try to do the following but i have some problems :

1/ Backup a Windows Computer (C:\, System State...) with SDR ON, on a deduplication storage device ==> OK

2/ When the backup is done, duplicate the backup sets on a USB Disk Drive ==> OK

3/ Create a customised SDR disk with the server i've just backuped ==> OK

4/ Plug the USB disk on the crashed server ==> OK

5/ Boot on the crashed server with the SDR dvd ==> OK

6/ Select the correct .DR file ==> OK

7/ Select the option The data is located on devices locally attached to this computer ==> OK

8/ Select the USB disk ==> KO

I cannot see the USB disk on the device list. The device seems to be well recognized  because i'm able to browse all the .bkf files, also some .cfg files

Question : is it possible to duplicate backup sets on an usb disk and then recoverer the computer from it ? Am i doing something wrong ?

Thanks in advance