Windows 7: Diskpart hangs running 'clean all'

Thank you very much for all the help and advice, I'm pleased to say following the advice it's now solved and the disk checks out fine.
I've no idea why it froze or whatever but its now clean re-formatted and seems to be working OK

hi, i'm having the same issue with a larger drive- a 2tb g-drive- i'm using windows and i read from their site that this drive comes pre-formatted for macs.. so i followed the directions on selecting the drive and running diskpart/clean all. it is now about 20hours and it is not done.. should i also kill this and only do clean? i already see the drive on the Disk Management area showing all space unallocated- tried to initialize but it says it is being cleaned- even after I ended the Command from the task manager. Any sugestions? This is just an external drive on firewire and it is brand new.. now I'm wondering if i really had to do all this.- Now i can't even see the command window- thanks

There is no reason to run Clean All except making data unrecoverable by most methods. Any other reason like writing zeroes to the boot sector to overwrite bad or conflicting code can be accomplished by the Clean command. Reboot the computer and run Diskpart Clean Command .

Make sure you have the latest BIOS update as this is sometimes required to handle drives that large.

If you plan to install to the drive, unplug all others and use the booted installer Custom>Drive options to partition and format: Clean Install Windows 7

Otherwise partition in Disk mgmt. That may have been all you needed in the first place - to delete, Create and Format in Disk Mgmt. Partition or Volume - Create New. The Clean commands really are only needed for troubleshooting purposes otherwise.