I purchased this HD to use as data storage while I move from WinXP to Win7.
My WinXP is on a 500GB drive partitioned into 6 drives, with the OS on C: and the others for data, games, misc. Makes it easy to do a daily backup of drive D and have all my data saved.
I bought a 1TB drive for Win7 and installed ok, partitioning it to 6 drives during the install. I copied my data from the WinXP HD to the Win7 HD using an external HD. I then thought if I move my data drives to another HD I can just plug in the HD drive for WIN7 or WinXP, leave the data HD always on, and not have to worry about copying files back and forth from my WinXP drive to the Win7 drive. So I bought the Toshiba 1TB.
I formatted the new Toshiba in Win7 partitioned as 6 drives. Worked fine. I unplugged the Win7 drive and plugged in the WinXP drive and it wouldn't recognize the new HD. Turns out WinXP only recognizes MBR but Win7 uses GPT. I then tried partitioning it in WinXP but it wouldn't. I tried EaseUS Partition Master 9.2.2 and it says it is 2TB not 1TB! Partitioning fails. I tried Hard Disk Low Level Format Tool and it won't run because it says the HD capacity is 0 bytes.

How can I restore this HD to it's blank out-of-the-box condition?

JJMartin,

if you can put drive to external enclosure and connect it to working Win7 PC.
You can also try with bootable linux(Ubuntu,..) CD/DVD, hirens boot,...
With single drive and many partitions on it, you are not safe from drive fault.