Summary: I was replacing a bad hard drive on my desktop computer and wanted one that met my needs. This WD filled the bill in that I was able to restore all the original operating system and drivers on it and the computer is now working great.
Summary: Did a chkdsk and format before installing Win 8 twice, Vista Ultimate once and then Win 8 again, as an update. I forget how many times I formatted. Talked to MS and was told that all Win 8 packages are updates, except for OEM packages. Mine was a retail. Still working just fine and looking forward to another five years.
Summary: Ok-- bought one of these to build a PC for my kid last Xmas (2012)-- ended up failing right before Xmas (2013)-- was able to retrieve most useful data from it using a external USB adapter on another PC. The good news is that WD's warranty system works good and actually had the replacement for the failed drive to me only a couple days after new one arrived (so now I have a spare). Not the best experience, but WD service was great.