We use SCCM to image our machines.  It works on 15 different Dell models from Optiplex to Lattitude's.   But it does not work on the Dell Optiplex 7050.  Each time you boot up off of a USB drive and connect to the SCCM server it does not see any C: drive.   Once you boot up off of a USB you can press F8 and bring up a CMD window.  Then if you do diskpart - list disk it does not see the C: drive, it only sees the USB drive as "disk 0".   We've updated our boot.wim with the 7050 mass storage drivers yet it still does not work.   Is there a workaround for this?