Just though I'd post my experience on the up grade. It's going to be a little long winded so hold on! 1. Bought Series 3 on ebay w/o HDD 2. Instantcaked a random 320GB HDD with no problems. (mounted HDD and CDROM to sata expansion card) 3. Bought the Hitachi 3100 1TB from Newegg (during their $70 sale) 4. Used WinMFS to upgrade the new disk. a) Made a truncated backup of the 320GB drive with a NexStar - 3 external case (made by Vantec) b) Swapped the 1TB and did a restore. (forgot to supersize it but did it later w/o any problems) 5. Booted the Tivo with new drive. After the "few minutes more" screen it green screened. I left it alone and it kept rebooting and getting to that point and repeating quickly. After about the 8th reboot it stayed on the green screen for much longer. It took about an hour on the last green screen but after that success! Please feel free to contact me with questions.