I just got a WD 640 to replace my 200GB Seagate 7200.8. I downloaded the WD Windows clone utility in advance to check it out. For some reason it thought my system wasn't fully enabled for more than 137 GB. WD recommended the DOS version, but that meant buying a floppy drive. So I downloaded Acronis trial version. Works perfectly for 15 days, haven't decided whether it is worth 50$ to keep it though. But the trial version is fully functional and easy to use, even for computer illiterates like me. I have seen some posts on Acronis' furoms about difficulties uninstalling it. But there are help threads for doing it if causes problems.