I had Windows 10 installed on my PC then I created a new volume from C drive and then installed Ubuntu from live environment.
It said installations successful and everything OK. But after restart no Windows options were found in Grub menu. So I shut down by pressing switch. Then when I restarted PC it booted in Windows. And then I couldn't find the hard disk on PC.
I went to device manager found the disk but it was not showing anything may be unallocated. I tried to assign letter or anything else, but no option was available.