I moved a 3TB drive that had been upgraded in a Roamio basic to a Roamio Plus. I thought it would treat it as a blank drive but it booted up but with many error codes showing on the screen. Eventually, I wound up wiping the drive with "HDD LLF Low Level Format Tool". http://hddguru.com/software/HDD-LLF-Low-Level-Format-Tool/ Select the option to "quick wipe" the MBR and partitions (takes about 5 seconds). After reinstalling the drive in the Plus, the upgrade went as expected and been running fine since.