When I got my HR20 and two HR21s, I took out the 3 internal hard drives and installed 3 WD 1TB drives inside. Since the original HR20/21 drives had no recordings on them I decided to partition/format them for use inside my PC. However, I have been unable to format any of them... In fact, my PC just doesn't seem to be able to recognize them.... I used the Disk Management tool in WindowsXP. Any suggestions? Thanks!