Sorry if I shouldn't have started a new thread..... I just received my Roamio (basic) and am currently running the WD Data LifeGuard Diagnostics EXTENDED TEST (8 hrs down 12 hrs to go) on my WD30EURX 3TB HDD. I am a Comcast/Xfinity customer, I have the M-Card, and have not unboxed the TiVo yet. The TiVo was purchased directly from TiVo with Lifetime Service, and was likely shipped Pre-Activated. Should I swap the HDD BEFORE initial power up and M-Card set-up.... or get it working as shipped from TiVo and then swap the HDD? Thanks for your help!