I've been struggling for months to get the auto backup under W10 to work. I'm using Parallels v11.2.2 installed under El Capitain. I initially had a problem with the drive letters changing every time I opened W10 but some helpful people here told me how to deal with that. The issue I have now, and for the past several months is that the built-in backup program under W10 does not see any drives to back up to even though those drives are visible when I open Explorer. That is, when I open the settings window to specify which drive to back up to, there aren't any choices available. There is a "Network" button in the backup program that I thought my be used to show all the external drives but that requires me to insert my network "credentials", which I do not have since there really isn't a true network. Is this a Parallels issue or a W10 issue, and does anyone have any ideas how to fix it?
Ok, I've discovered what was wrong so I will post this hoping that it may help someone else in the future. Actually the fix was easy once I discovered what was wrong. In the Parallels Settings under Hardware\USB & Bluetooth\USB Connection Preferences I had never moved the backup drive over from W7 to W10. Once I did this I was almost there but not quite. The Parallels message on the screen states that some (and this is one) changes require the virtual machine to be restareted in order to take effect. I restarted W10 but this did not work for me. I had to shut down Parallels itself in order for the Backup & Restore program to recognize the external disk. I'm glad I found the answer but still do not understand why Explorer could see the drives but Backup & REstore could not.
Please check External HDD file system. If the format doesn't have Read/Write compatible with Windows file system then it will not work.
I'm also trying to tackle a similar problem, but your solution did not work. Basically what I am trying to accomplish is that I have purchased a 4TB drive and I want to use it to backup Mac and Bootcamp/Parallels Windows to the same drive. I have formatted it half for Mac (Mac OS Extended Journaled) and half for Windows (NTFS). I can use both partitions fine as far as read/write operations in each respective OS. However, the problem comes when I try to use the backup utility (Windows 7 version because I want a system image included) in Windows 10. No matter how I try to link the drive to Windows through Parallels it doesn't work: -If I just mount it to the Mac side and use it as a "network drive" it shows up as prlSF drive type, which is not NTFS so that will not work for backups. -If I mount the drive as a USB device through Parallels into Windows directly it shows up as NTFS, but the backup quickly fails with the error "The volume does not contain a recognized file system." (Error code: 0x800703ED). -If I setup the drive as a hard drive image through the Parallels VM configuration I get the same issue as above with the unrecognized file system. So basically no matter how I go about this I cannot backup Windows from within Parallels. I run my VM as a dual boot Bootcamp and Parallels VM. However if I boot directly into Windows via Bootcamp and take the same drive and plug it in it has no issues backing up to the drive whatsoever. Also, I decided to give a shot at backing up to a completely formatted NTFS drive formatted within Windows (from Bootcamp not Parallels), so no crazy partitions and the issue remains. It fails in Parallels and succeeds in Bootcamp with the same problems as above. Ideally I would like to be able to rely on backups happening automatically when I start my VM. I planned to do this by setting my NTFS partition as a drive image through Parallels VM configuration. This allows me to have one partition (TimeMachine) mounted to Mac, while the other partition is mounted into Windows simultaneously. Unfortunately, Parallels does not like when you then remove the external drive and boot Parallels without it. I figured it would act like the CD-ROM setting which just goes to Disconnected automatically when it's not connected, but Parallels gets really buggy with this kind of setup as well.
It's almost like the Parallels drivers somehow inhibit the backup process. Being a software engineer myself, I'm sure one of your engineers could look at it and see what I'm saying.
