Follow Windows installation first and Ubuntu second.
For fresh installation of both OR Ubuntu not detecting existing partitions / Windows installation:
1. Boot into Ubuntu 14.04 Live
2. From Unity, select GPart 2.
3. Create 2 partitions using GPart 2 - one partition with NTFS for Windows & the other with ext4 for Ubuntu.
4. Now Quit from Live boot.
5. Insert Windows 8 usb/disk and install to NTFS partition.
6. Now, install Ubuntu with / and /swap partitions
If BootMenu is not visible with Windows & Ubuntu,
- press "Shift" key after POST or system on.
- Select Advance options of Ubuntu
- Select "Update GRUB"
- Now, the action can detect Windows installation and will configure BootMenu accordingly.
- After system reboot, you can see the BootMenu for selecting Windows or Ubuntu
Also read:
http://itsfoss.com/install-ubuntu-1404-dual-boot-mode-windows-8-81-uefi/
