After windows updated to the v1607 build 14393.51, everything seemed fine. I had EaseUS todo backup free version 9.2 on my d: drive. Along with many of my programs i.e. FSX 10, Trainz, Silent Hunter IV... I went to do a file backup, (I had done a system backup with no problem). I was doing only the d: drive, but about 80% done it crashed, so I decided to try later. Then I went to load a game that was on d: and it said it wasn't there. I opened windows explorer and clicked on d: and it showed the drive was empty. I rebooted and looked again and the drive didn't even show up. I restarted and went into the bios and that HD didn't show up either. It was gone. I opened the case and moved the sata cable to another sata port. Then started windows again, and d: was back with all the files. I did try to backup again and it did the same thing. I move the sata back to the port it had been on, and it was all working. So I've uninstalled the EaseUP backup tool from my d:. So far everything is working. I did a bios update to my gigabyte motherboard and ran a scan on d:. It was fine. Never had a problem like this before. Only after this last update did anything like this happen, especially even causing the MB to not show the drive. Nothing happened to my c: or e: drives. On the d: and when I tried backing up. Any Ideas what could have caused this?