I have one SSD and one HDD on my PC. SSD runs Windows 7, i want to set up Ubuntu as dual boot on the HDD. I downloaded the WUBI.exe for 16.04 and installed it to my HDD. After first startup i got some errors like "root file system not defined" after it successfully booted to the main Ubuntu screen. I googled a bit and it seemed like (i was using both the HDD and SSD prior to that in Windows) my HDD was in NTFS and i needed to set up Ext4 first of all. So i downloaded Partition Wizard, and changed the HDD from NTFS to Ext4. Upon booting Ubuntu i get the error "error starting windows" for file "\ubuntu\winboot\wubildr.bmr". I can't boot Ubuntu, Windows 7 works fine, my HDD is not visible in Windows 7 anymore. How can i fix that?
I don't know alot about system settings, but the fact that my HDD is not visible under Windows should be ok, because Windows can't react Ext4. How can i repair my HDD tho, if i isn't visible under Windows anymore?
EDIT: I formatted the HDD again with partion wizard as EXT 4 and made a bootable USB stick with Ubuntu on it. After booting the stick to install Ubuntu on the HDD, it doesn't find the HDD in the installation menu and i can only select the SSD where my windows is installed. I don't want to partition the SSD. What's wrong here?