I am using windows 10 ( upgraded from 8.1 ) and I installed kubuntu 15.04 using a bootable usb. I installed this into sda5 with 40GB capacity. I also created a swap partition of 8GB. After installation when it asked me to reboot, I did so. No GRUB menu was being shown and the system went directly into windows 10. Inside windows, the partitions (40GB and 8GB) were shown as RAW file systems and I am asked to format those when I try to access them from Windows. In UEFI boot settings, I had enabled legacy boot and disabled secure boot for installing kubuntu.
Please help me in bringing out the GRUB menu so that I can use kubuntu from the start itself. Otherwise I have to go to UEFI boot options each time and select boot from Notebook Hard disk option. Also when Windows starts it shows "Scanning and repairing drive(J)". (One of the above mentioned partitions)