I'm in the same boat. I tried just about everything. The Acronis guys had me do all sorts of stuff, re-install, create a cd (many cds...), install snapapi, and so on, and so on, and so on, all leading nowhere. That's what happens when you try cook-book fixes without understanding the problem. The basic problem is that Acronis disk clone software has a bug. I have been thinking about this problem quite a bit. Here's my assessment of what I think is happening: When Acronis attempts to clone the drive, I hear the drive clicking and buzzing away - clearly the software is busy. I suspect Acronis is collecting all sorts of data and doing some kind of check before it begins writing onto the target disk. For whatever reason, Acronis software gets confused and skips the writing procedure. Because Acronis sometimes works and sometimes doesn't, that suggests (to me) that the data on the source disk has changed and that sometimes Acronis likes it and other times does not. When it does not, it does not write onto the target disk. Here's my logic: I know the drives in perfect shape (they are brand new Western Digital WD3200SBs, I have checked them with chkdsk /r/f many times) and I know my Windows XP installation checks out (I did sfc /scannow, etc, etc, etc... and many other system checks). I have had exactly the same problem with my old drives: a 120MB Western Digital and a 120GB Maxtor over the past 2 years. Over the past two years, I have religiously maintained my system, and have incorporated all of Microsofts updates. I do not use "funny" software - it's all bought/paid for, and in the case of Spybot, I sent in a donation. This problem has been random over two years. So it's not the drives or the "system". The only other variable left is the data on the disk. My conclusion: It's got to be the data on the hard drive that Acronis is reading which screws up Acronis. For some reason, when that data is "just right", Acronis starts to work and I am able to do disk cloning. Other times, the source disk data screws up Acronis. I have no idea what data Acronis needs or what it does with it, but the behavioral evidence points to Acronis getting screwed up when it reads the source disk data just prior to writing to the target disk. At this point, we all need Acronis to chime in.... Cheers, John.