I had Win 10 Enterprise running in a VM and decided to install it on a dedicated hard disk. The system is a Dell 3847 i5, 8GB Ram, 2-1TB drives. I cloned my daily Driver Win-7 Enterprise 64-Bit to the spare hard drive, so I would have all my files and disk structure on the new drive. Then formatted the cloned copy of Win-7 C:\ for installation of Win-10. Booted of Easy2Boot and installed Win-10 Enterprise 64-Bit, no problem. Installed Office and some other software. So far so good. At this point I decided to make an image of Win-10 installation so far. And that went fine. After the image was made I booted back to the Win-7 hard disk and check eMail and did some other stuff, and thought since the Win-10 disk was off line, I could run Chkdsk on it without having to do the re-boot thing. Big mistake. It got to 10% and then ticked off one error after another. Reparse points, and many others. I figured I'd let it run. After 30 minutes I tried to Ctrl-C out of Chkdsk. No response. I didn't want to close the window, so I just let it run. After about an hour it finished, with thousands of errors. Somewhat annoyed, I restored the Win-10 image and re-booted back into the Win-10 system, and ran Chkdsk /f /v from the Win-10 elevated Cmd prompt. It said it would run on the next re-boot, and I let it, and it didn't find any errors. So it looks like the Win-10 image was ok. One thing I notice throughout this whole episode, was that when I started up the Win-10 system there was heavy access to the Win-7 disk, even though it wasn't active, just a slave. Seemed a bit weird, but I didn't think anything of it. When I re-booted into the Win-7 system, I was greeted with "Windows has found errors on your hard disk, and needs to run Chkdsk to fix them" So I let it run, and everything seemed to come up OK, but I figured the Win-7 installation might have been hosed, so I restored it from an image just in case. As near as I can figure out, Win-7 Chkdsk isn't compatible with Win-10, and for some reason Win-10 will alter or somewhat hose up a Win-7 hard drive if is connected at the same time. Although this makes no sense because the secondary hard drive shouldn't have anything to do with anything. I guess the next step would be to set up a dual boot system as others have done. But I thought it would be less hassle, just to plug in a separate drive, and then boot from that drive if I wanted to run Win-10 and then just re-boot back to the Win-7 hard disk. Guess not. That way I could keep my Win-7 Enterprise Daily Driver system separate from the Win-10 setup. But it looks like the only way to do that is to physically disconnect the Win-7 drive, boot to Win-10 without the Win-7 disk connected. Not hard to do, but makes copying files between the two systems impossible. Anybody else have problems with Win-7 Chkdsk on Win-10 systems? .