Install linux Ubuntu system under win7, indicating that there is no root file system. Please return to the partition menu to correct this error.
You can't install with a virtual CD-ROM drive, because ubuntu still needs to read files to complete the installation after restarting. So just burn iso into a CD or use a USB flash drive, or put it directly in the root directory of C drive, but it will be more troublesome. You can visit ubuntu's Chinese forum.